BS: Hurricanes & Earthquakes - related?

Subject: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 21 Sep 17 - 06:00 AM

Yes yes, Mexico City is prone to earthquakes. Hence this question.

But I was wondering, with all that storm surge pulling water into the gulf adding weight to the Earth's crust locally then releasing it, it must be giving the crust a kick (in geological timescales). And several kicks this year.
Look at how glass behaves - it is a super-cooled liquid after all (no latent heat of fusion). If it has a crack/scratch and you tap it - it splits/lengthens. cf the crust.

FWIW
The Gulf of Mexico has a mean sea level 6ft above the Pacific side of the isthmus. Due to tidal drag.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 06:09 AM

Mr Red. A qualified yes. The same as filling large reservoirs or injection(eg fracking) can create microseismic events, as also can pumping from oil and gas reservoirs.

http://www.nature.com/nature/journal/v459/n7248/full/nature08042.html?foxtrotcallback=true


https://sites.ualberta.ca/~vanderba/papers/DKV09.pdf

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Teribus
Date: 21 Sep 17 - 06:20 AM

I thought that the tidal surge you get from large tropical storms are caused by high but very localised pressure difference and wind speed pushing, acting on, the water that was already there, I don't think that any additional water has been pulled in from anywhere.

Seen and experienced the effects of two hurricanes close up while at sea on an RN ship acting as "Hurricane Guard Ship" out in the West Indies. This Hurricane season seems to be a very active one with fierce Hurricanes sweeping in one after another which makes relief and emergency work extremely difficult.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 21 Sep 17 - 06:28 AM

No link has ever been found between tides and quakes, so it seems unlikely.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Nigel Parsons
Date: 21 Sep 17 - 06:39 AM

Although no link has been found yet, we are seeing new extremes of weather, and are better placed to link cause and effect than we have previously been.
I wouldn't rule out there being a causal link.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 07:03 AM

K of H. FYI Proceedings of the National Academy of Sciences


https://www.livescience.com/55448-how-tides-trigger-san-andreas-earthquakes.html

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Jim Martin
Date: 21 Sep 17 - 07:07 AM

The thing I can't get my head around is that the earthquake occured to the day 35 yrs ago when one occured & when earthquake drill was taking place somewhere!

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 21 Sep 17 - 07:09 AM

Tides are caused by the difference in gravitational potential of the moon and the sun on opposite sides of the earth. Tidal forces do act on other bits of the earth than water, but this hasn't changed significantly for hundreds of millions of years. Earthquakes are caused by motions of tectonic plates, and the largest ones are subduction earthquakes where one plate is thrust below another.

Teribus and Keith are right, there is no link between tides and quakes, and the storm surge caused by a hurricane (which is not a tide, though it has the same effect) will have no effect on the motions of tectonic plates.

Microseismic events maybe, but not of any significant magnitude and not at any significant depth. The point about fracking is that material is pumped at high pressure deep underground.

What Liu, Linde and Sacks call "slow earthquakes" are movements of plates which occur over long periods of time, and are not destructive

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 07:29 AM

Sorry David Carter you are incorrect. The entire crust is stressed and requires varying amounts of additional imposed stress to create failure and hence earthquakes. Look at any geological map and it is smothered in faults. Each one has created earthquakes when movement has occurred and retains that capability to an extent dependent upon numerous factors. Suffice it to say that in some areas a very slight increases in stress create minor earthquakes. In other areas far greater additional stresses are required to cause failure, thereby creating earthquakes of far greater severity.
Simplistically any area of the earth is an accident waiting to happen.
Frequency and severity of earthquakes is a function of multiple factors including the stress regime where the earthquake occurs.
Daily tide stresses were previously thought to be insufficient, recently, however, they have been found to correlate significantly with small earthquakes, just before large earthquakes occur.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 07:54 AM

" Earthquakes are caused by motions of tectonic plates, and the largest ones are subduction earthquakes where one plate is thrust below another."
No plate margin near UK yet quakes in last 50 days below.
http://www.crondallweather.co.uk/earthquake.html#.WcOn5saX3IU

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 21 Sep 17 - 09:43 AM

Without wanting to come over all Paul Hogan here, those aren't earthquakes. The strongest of those was 4 on the Richter scale. An increase of 1 on the Richter scale corresponds to an increase in energy released of a factor 31.6. The recent Mexico city earthquake was 7.1, so energy released a factor 45000 greater than the strongest of those UK events. I am not sure whether thats a subduction earthquake. Sumatra 2004 and Tohoku 2011 which were subduction events were 9.1 on the Richter scale, which according to my calculator app releases 44.5 million times as much energy as the very strongest of those UK events.

Now you do get moderately strong earthquakes away from subduction zones, famously the New Madrid earthquakes in the central USA in the early 19th century. The San Andreas fault is a lateral fault so the plates are sliding laterally past each other (rather than one under the other as in a subduction zone). This type of fault likewise gives rise to moderately strong earthquakes.

The recent Mexico city earthquake seems to have triggered an eruption of Popocatepetl. Some people were briefly concerned about the proximity of the 2004 Sumatra earthquake to Toba Lake. And you really, really don't want an eruption of Toba lake.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 21 Sep 17 - 10:13 AM

no link between tides and quakes

A very definite and sweeping statement about a "science" that most geologists (like my bro-in-law) will tell you is an art. Predicting earthquakes that is.

In these contexts I invariably point to friction and notably stiction. If you want an old mechanical instrument to overcome that last bit of uncertainty what do you do? Lets take the familiar barometer. Do you tap it gently and see if there is any minor change? Or on lathes add vibration, commercially? Even with lubrication abounding.

Now could we look at a fault line? And by magnification compare it to two metal surfaces rubbing against each other. Those surfaces look similar to the imagined fault line (which can be 50 miles wide). So a low pressure area lifts the water, and after it has gone the water rocks in a second order oscillation decaying exponentially in amplitude. An effect well seen in Lake Michigan because of the shape thereof. Timescales are days and weeks.

Hence that tap tap from about three major hurricanes. And an earthquake waiting to happen. All it needs is to exceed the current threshold.

And isn't one proposed solution (on the San Andreas) to large quakes to pump water into the fault line to lubricate it? Thus causing more frequent and less devastating ones.

Not proof, but a reasoned scenario cf sweeping NO.

ever sat as a weather front arrives? I have and on my timescale - relatively modest though it may be it goes "BANG"!

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 21 Sep 17 - 10:14 AM

It's an idea which can't be dismissed out of hand, but in general we know what causes major earthquakes in the particular places they occur. Localised water pile-ups are generally sea surface-only phenomena (unlike tsunamis) caused by wind or changes in air pressure. The energy generated in those events in the sea is minuscule compared to that of the long-term build-up and release of stresses that lead to major earthquakes. It's also worth remembering that most major earthquakes happen several, or many, kilometres below the actual epicentres, well away from the influence of what might be going on on top.

Phreatic volcanic eruptions are a different matter...

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 21 Sep 17 - 10:33 AM

I had a skim through and it's a fascinating paper. It's not the storm sure that causes the slow quakes, it's the drop in atmospheric pressure associated with the storm reducing the vertical stress on the crust. Also, not all slow earthquakes are caused by typhoons apparently.


"What Liu, Linde and Sacks call "slow earthquakes" are movements of plates which occur over long periods of time, and are not destructive"

No, they are still earthquakes just a different type of quake; this phrase would have been picked up in peer review (or before almost certainly but the editor). They move immense amounts of crust and play a role in triggering ordinary earthquakes.


"I don't think that any additional water has been pulled in from anywhere."

A storm is not a closed system so exchanges of all sorts will occur between it and the environment it exists in and air, water, heat etc will all move in and out of the storm's vicinity.


Pedant's note: The Richter scale isn't used anymore and hasn't been since the seventies.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 11:17 AM

Stu. It is an interesting field of study and research tends to indicate that it is subtle changes in atmospheric pressure on pore water that acts as the causative mechanism in some cases.


http://adsabs.harvard.edu/abs/2015AGUFM.S13B2835W
It can be argued that barometric pressure variations may cause thresholds to be exceeded and trigger minor earthquakes or even initiate major earthquakes. It is also argued that the massive rainfall during typhoons/hurricanes can trigger landslips thereby altering the quasi equilibium of the crust leading to a time delayed earthquake as equilibrium is sort. It is an active field of research and slowly changing many long held views.

http://www.newsweek.com/hurrica

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 21 Sep 17 - 12:20 PM

Earthquakes will not be forever although we can trigger earthquakes by injecting water deep underground acting like a lubricant between rock layers. This was proven 57 years ago when the Air Force injected water and nerve gas deep beneath Colorado Springs.

As long as tectonic plates float on top of liquid rock they will run into one another producing earth quakes. If a fraction of a percent increase or decrease of gravity triggers an earthquake so be it but this is still a planet of geologic motion that will produce earthquakes should the molten core freeze before the red giant sun approaches the Earth. The final earth quake will be the Earth tearing apart as it descends into the sun.

While earthquakes may occur anywhere the frequency of earthquakes around the ring of fire in the Pacific is a remnant of the disruption caused by a massive impact that surprisingly created our moon.
It is also the reason the upwelling of the heaviest metals like gold are also found surrounding that great circle..

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 21 Sep 17 - 12:26 PM

edit

"this is still a planet of geologic motion that will produce earthquakes UNTIL the molten core freezes before the red giant sun approaches the Earth. The final earth quake will be the Earth tearing apart as it descends into the sun." if the core freezes by then.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 21 Sep 17 - 12:27 PM

Studies have been done to search for correlations, but none have been found.
The research quoted by Ians referred only to very deep and very minor (less than 1 on Richter) tremors, not what anyone would call an earthquake.

No link has ever been established between actual earthquakes and the local state of the tide, maritime or geo.

It is hard to see how such a link could have been missed.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Nigel Parsons
Date: 21 Sep 17 - 12:29 PM

The original question was about Hurricanes & earthquakes

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 21 Sep 17 - 12:41 PM

In our universe all things are related at some level but not at a significant causal relationship.

I used to think religion was related to an anticipated nuclear war/
Now I relate a secular and ignorant Trump to a nuclear war.

Actually nuclear weapons are most related to nuclear war.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Teribus
Date: 21 Sep 17 - 12:58 PM

It was more the idea of a tropical storm, in this case a hurricane dragging water in from the Atlantic into the Gulf of Mexico or into the Caribbean seem rather bizarre.

Two large storms that caused massive flooding in areas where the low pressure stem driving the storm did not more in the predicted direction and the storms coincided with a period of High Astronomical Spring Tide. The two storms were:

1: On the night of Saturday, 31 January 1953 in the North Sea caused major flooding in the Netherlands, Belgium, England and Scotland. The Low as it passed over the UK pushed water northwards in the North Sea, then instead of tracking North East as these storms normally do it tracked directly East and as the storm made the European mainland the mass of water held to the North of the North Sea the storm wind swept them southwards to coincide with the HAST.

2: 1970 Bhola Cyclone a devastating tropical cyclone that struck East Pakistan and India's West Bengal on November 12, 1970. It remains the deadliest tropical cyclone ever recorded and one of the deadliest natural disasters. Up to 500,000 people lost their lives in the storm, primarily as a result of the storm surge that flooded much of the low-lying islands of the Ganges Delta.

In both cases it was the water already in the North Sea and in the Bay of Bengal that did the damage - no water was dragged from anywhere else.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 01:10 PM

Eathquakes, temblors, tremblors are all the same thing. The unit of measurement is the moment magnitude(similar to richter for intermediate values-more accurate for higher values)
As I said previously research is ongoing, and instrumentation is   becoming more sensitive, as is computing power and analysis. %0 years ago the analysis carried out today would have been merely a dream, with each passing decade more and more is possible(egSchlumberger cutting edge techniques and instrumentation)
A lot of the relevant science is in it's infancy. I think some real progress is very close. Part of the problem is that today science is divided into increasingly specialised compartments. In reality there is no such beast as a geologist anymore, the field is too wide.
While we know much about seismology, rock mechanics and soil mechanics and meteorology, cross fertilisation between the disciplines is too much of a rarity. The thread under discussion highlights the problem admirably.

https://www.earthmagazine.org/article/blame-it-rain-proposed-links-between-severe-storms-and-earthquakes

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 21 Sep 17 - 01:39 PM

Changes in air pressure over the sea are not transferred to the sea bed. Water is drawn in to compensate for a reduction, and vice versa.
Over land, hurricanes rapidly weaken.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 21 Sep 17 - 02:22 PM

"As long as tectonic plates float on top of liquid rock"

The plates don't float on molten rock, rather the rock underneath (the mantle) exhibits plasticity and it's the convection of this ductile rock that drives plate movement.


"no water was dragged from anywhere else."

Like I say, it's not a closed system and all the water in all the seas interact. Sea water is dragged around the worlds oceans by currents.


"Changes in air pressure over the sea are not transferred to the sea bed."

Wrong. High pressure systems depress sea levels and change the density of seawater, which is compressible. This pressure will be transferred to the seabed as the sit sits open top of that.

Everything is interconnected. Everything affects everything else. As I said earlier, these are NOT closed systems and interact with their surroundings. It is that simple.


"Over land, hurricanes rapidly weaken."

Er, yup.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 02:42 PM

Salinity and temperature affect density, Pressure on the seabed is a function of density and depth. Depth is modified by meteorological effects as mentioned, and these are amplified in enclosed areas.
NOAA "Local wind and weather patterns also can affect tides. Strong offshore winds can move water away from coastlines, exaggerating low tide exposures. Onshore winds may act to pile up water onto the shoreline, virtually eliminating low tide exposures. High-pressure systems can depress sea levels, leading to clear sunny days with exceptionally low tides. Conversely, low-pressure systems that contribute to cloudy, rainy conditions typically are associated with tides than are much higher than predicted."

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 21 Sep 17 - 02:47 PM

You tell 'em, Stu. In the end, real science will always win out. 👍🏼

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 21 Sep 17 - 03:38 PM

The effect of pressure upon the density of seawater is really, really small. There is a calculator here.

So I am not convinced that a significant fraction of an atmospheric pressure change is transferred to the seabed.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 21 Sep 17 - 03:48 PM

Core, mantle or crust, its all rock in flux to me.

Some claim radioactive elements keep the core hot more than gravitational pressure.

Stu do you have a degree in Physics, geology, chemistry ?

Of course a PhD is a bit more reliable but not mandatory, except for employers. I love Earth science. We can practically touch it.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 21 Sep 17 - 04:22 PM

For seabed pressure you need to calculate the hydrostatic head of seawater. This runs .433 to .435psi/ft depending on temp and salinity.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Nigel Parsons
Date: 21 Sep 17 - 05:00 PM

From: Iains - PM
Date: 21 Sep 17 - 04:22 PM

For seabed pressure you need to calculate the hydrostatic head of seawater.

Surely that should be "plus the atmospheric pressure immediately above the seawater"

I only went as far as A-level physics, but I can still spot obvious errors in statements.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 21 Sep 17 - 06:44 PM

Well seabed pressure(?)/hydrostatic pressure/atmospheric pressure have always been with us. In the overall scheme of things, any effect of variations in them that might impact on the earth's crust, in which severe earthquakes usually happen at great depths, is minuscule. So the null hypothesis is that, as there is no evidence for those phenomena being causes for major earthquakes, they have little or no effect on seismic phenomena. Science can go no further without your evidence to the contrary. You have precious little such evidence, and just a reminder that speculation and flights of the imagination are not evidence.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Nigel Parsons
Date: 21 Sep 17 - 07:37 PM

From: Steve Shaw - PM
Date: 21 Sep 17 - 06:44 PM

Well seabed pressure(?)/hydrostatic pressure/atmospheric pressure have always been with us. In the overall scheme of things, any effect of variations in them that might impact on the earth's crust, in which severe earthquakes usually happen at great depths, is minuscule. So the null hypothesis is that, as there is no evidence for those phenomena being causes for major earthquakes, they have little or no effect on seismic phenomena. Science can go no further without your evidence to the contrary. You have precious little such evidence, and just a reminder that speculation and flights of the imagination are not evidence.

And I thought that you insisted that the Scientific method didn't deal with proofs.

This thread seems to put forward a theory, which, in the absence of any evidence against it, should be allowed to stand as a theory.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 22 Sep 17 - 03:52 AM

As theories go - would anyone care to compare my posit with one that has the hurricanes and the suffering, and an earthquake in the vicinity - a direct result of God (whoever she is) punishing us for electing Trump?

And............... on the Wreckter scale, which will prove more devastating?

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 22 Sep 17 - 03:53 AM

" they have little or no effect on seismic phenomena"


From the National Oceanic and Atmospheric Administration.""Local wind and weather patterns also can affect tides. Strong offshore winds can move water away from coastlines, exaggerating low tide exposures. Onshore winds may act to pile up water onto the shoreline, virtually eliminating low tide exposures. High-pressure systems can depress sea levels, leading to clear sunny days with exceptionally low tides. Conversely, low-pressure systems that contribute to cloudy, rainy conditions typically are associated with tides than are much higher than predicted."
1)Therefore high pressure and low pressure systems modify the hydrostatic head of a column of seawater.
2)Low pressure can generate intense storms containing abundant energy leading to exaggerated tides,surges and wave action.
3)All these activities generate seismic noise
4)if the magnitude of the noise due to the above exceeds the failure point of adjacent stressed rocks failure will occur.
5)The failure may be seen as microseismic events or could be larger. This would depend on the nature of the system and the forces acting on it

Rock stress
http://dc-app3-14.gfz-potsdam.de/pub/guidelines/WSM_analysis_guideline_breakout_image.pdf
microseismic events
http://onlinelibrary.wiley.com/doi/10.1029/JB073i012p03945/full
Seismic noise
http://onlinelibrary.wiley.com/doi/10.1029/2007GC001814/pdf

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 22 Sep 17 - 04:14 AM

Stu,
Even if sea water density was significantly changed by pressure, which it is not, changes in atmospheric pressure are not transferred to the sea bed.
A fall in air pressure produces a sea level rise to compensate.
A barometric rise causes a sea level depression to compensate.
You can not have adjacent areas of sea bed with different hydrostatic pressures without creating a flow of water to even them out.

You tell 'em, Stu. In the end, real science will always win out.

He got it wrong Steve.

Wind however can produce such effects because the compensating flows are slower.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 22 Sep 17 - 04:57 AM

I am sure some will still want to argue!

meteorological triggering of earthquakes

rain triggered earthquakes
Haiti earthquake perhaps triggered by storm erosion


possible tidal correlation with earthquake swarms

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 22 Sep 17 - 05:08 AM

Mr Red's longer post contains the kind of reasoning that amounts to a hypothesis. The next step would be to gather evidence. The kind of speculations raised in this thread are neither evidence nor theories, though they may form a basis for seeking evidence. That's as far as it goes. Interested parties, off you go to find evidence. And Nigel, I didn't mention proof. I don't know where that's supposed to have come from.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 06:04 AM

"Stu do you have a degree in Physics, geology, chemistry ?"

No, I was doing a part-time self-funded PhD in vertebrate palaeontology until this time last year, when I was forced to withdraw after three years because my senior supervisor 'left' and no suitable replacement was found, and it turned out the specimen I was working on wasn't owned by my institution but was still partially in private hands and so I had to stop working on it. This put the kibosh on the whole endeavour and I was out. Appalling mess. I had just finished gaterhing the data on this specimen too, so that was three years pissed away.

Although I go my fees back, I spent at least as much again on travel, equipment etc and I couldn't budget for another seven years of research, so I'm hoping to do an MPhil and see how I go on from there.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 22 Sep 17 - 06:05 AM

From Ians' final link.
" The statistical test however did not prove a statistically significant correlation indicating a triggering effect of fault extension due to tidal loading. We also examined tidal effects to the already running seismic activity of the prominent 2000 swarm by comparing the tidal stress distribution in the investigated period with the distribution of tidal stresses in the occurrence times of each earthquake. The results show that these distributions are almost similar, which indicates that individual earthquakes occur independent of tidal stresses."

No correlation has been found between actual earthquakes and tides either, though there have been a number of studies that looked for them.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 06:36 AM

"Even if sea water density was significantly changed by pressure, which it is not, changes in atmospheric pressure are not transferred to the sea bed."

High pressure systems alter the density of the water throughout the water column, and this will of course affect pressure at the seabed. This an indisputable, observable fact.

The issue here is we're veering towards the usual Mudcat reductionism, and in this case that really means the argument is worthless. There is an effect of atmospheric pressure on the density of seawater, but it's part of a very complex system with literally millions of variables. What this means for plate tectonics I have no idea.

However, as the paper first link in Iain's original post makes clear, atmospheric pressure seems to affect seismicity and trigger slow earthquakes (and other events?). Does this happen at plate boundaries? I don't know, but it's not an unreasonable hypothesis to suggest it does.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 22 Sep 17 - 09:05 AM

High pressure systems alter the density of the water throughout the water column, and this will of course affect pressure at the seabed. This an indisputable, observable fact.

No, it is rubbish.
There is no significant change in density due to air pressure. The entire pressure of the whole atmosphere is equivalent to about 10m of water. Changes in pressure only centimetres.
Even a full 10m does not compress water!

Even if it did, air pressure changes would still not be transferred to the sea bed.
The actual effect of changes in air pressure is to raise or lower the sea level, which negates any pressure change at the sea bed, or at any given depth.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 22 Sep 17 - 09:15 AM

We were told at school that one property of liquid water is that it is virtually incompressible.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 09:18 AM

This discussion has given me invaluable insight into the way you structure and support your arguments Keith. Unlike many here I've always given you the benefit of the doubt.


"The entire pressure of the whole atmosphere is equivalent to about 10m of water."

This statement is utterly meaningless. I'm not arguing with you when your arguments are based on personal incredulity etc.

However, Keith's attitude does raise an interesting point, and one scientists wrestle with constantly. How do we communicate our science to people in a way they can understand? As a dinosaur worker this is made easier for me as everyone is interested in dinosaurs, but the sort of research published in Iain's original link whilst fascinating and quite wonderful is much harder to communicate in a way that helps people relate the research to their own lives.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 09:49 AM

"We were told at school that one property of liquid water is that it is virtually incompressible."

At a constant temperature and pressure.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 22 Sep 17 - 11:25 AM

"The entire pressure of the whole atmosphere is equivalent to about 10m of water."
This statement is utterly meaningless.

No, it is correct. Do you not understand?
The pressure of the atmosphere at the Earth's surface is equivalent to the pressure under 10m of water (or 76cms mercury.)

"We were told at school that one property of liquid water is that it is virtually incompressible."
Correct Steve.
At a constant temperature and pressure.

No Stu. Pressure has no effect on its volume.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Keith A of Hertford
Date: 22 Sep 17 - 11:27 AM

Stu,
"The entire pressure of the whole atmosphere is equivalent to about 10m of water."
This statement is utterly meaningless.

No, it is correct. Do you not understand?
The pressure of the atmosphere at the Earth's surface is equivalent to the pressure under 10m of water (or 76cms mercury.)

"We were told at school that one property of liquid water is that it is virtually incompressible."
Correct Steve.

At a constant temperature and pressure.
No Stu. Pressure has no effect on its volume.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 11:43 AM

http://pubs.acs.org/doi/abs/10.1021/jp0136260

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Teribus
Date: 22 Sep 17 - 12:06 PM

High Pressure Systems?

"A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, and a cyclone occurs in the south Pacific or Indian Ocean."

Anti-cyclones are storms caused by High Pressure Systems and are restricted to the bands of latitude North and South of the Equator known as "The Horse Latitudes" (Between 30 and 38 degrees North and South of the Equator).

"An anticyclone (that is, opposite to a cyclone) is a weather phenomenon defined by the United States National Weather Service's glossary as "a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere". Effects of surface-based anticyclones include clearing skies as well as cooler, drier air. Fog can also form overnight within a region of higher pressure."

Only time I have had to deal with water under pressure has been connected with the hydrostatic testing of pipelines and pressure vessels. All water contains minute quantities of air in solution. In conducting a hydrostatic test of a pressure vessel or a pipeline pressure is built up gradually to the point at which this included gas is forced out of solution. At this point a hold is made, and an air inclusion test is performed. The pressure drops slightly during this hold and the extent of the drop is noted along with the temperature both at the surface and on the seabed if you are testing a pipeline. Having acquired the pressure drop due to included air the vessel or pipeline is then cycled up to full test pressure - On achieving that everything apart from the instrumentation lines are locked off and sealed and pen recorders graphically measure temperature, pressure and time. The Test is conducted over a 24 hour period. The pressure in the vessel or pipeline is allowed to fluctuate within given parameters that can be fully explained due to included air, and temperature variations - atmospheric pressure is not considered as the system under test is isolated. A steady pressure hold within those explainable parameters indicates a successful test, an unaccountable steady drop indicates a leak.

The influence of atmospheric pressure on the density of sea water and on the seabed would I think be so miniscule to be completely insignificant.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 22 Sep 17 - 01:05 PM

Well I agree with that last statement.

An anticyclone isn't a storm. In an anticyclone the air is descending, which increases its pressure which warms it. Typically, a temperature inversion forms which prevents air rising. An anticyclone that is completely self-contained, with no influence from advected air, will tend to warm up in summer as insolation and the warming effect of the descending air outdoes heat loss from the ground by radiation (the sun is higher, therefore stronger, and shines for more hours). The opposite happens in winter, so large anticyclones, especially the ones over landmasses, can get very cold, such as the one that forms over Siberia in winter.

Happy equinox, world.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 22 Sep 17 - 02:04 PM

"but the sort of research published in Iain's original link whilst fascinating and quite wonderful is much harder to communicate in a way that helps people relate the research to their own lives"

How right you are.
Hydrostatic head of fresh water is 0.433psi/ft
minimum atmospheric pressure measured 870mb=12.62psi/ft
Maximum atmospheric pressure 1083mb=15.71psi/ft
The difference is 3.09psi=7.1ft as a water column
Therefore the difference between minimum low pressure and maximum high pressure is equivalent to a maximum change in hydrostatic of seawater of 7.1psi BUT low pressure diminishes sea level high pressure increases it. Note I only used fresh water andhave not introduced temperature. Looking at the numerous bars on ship's plimsoll line gives an indication of how the story can complicate.
I hope this clarifies the issue. Having spent years doing these calculations on a daily basis I tend to take the concepts for granted.I do not offer it as an excuse if I have given a poor explanation though


I hope

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 02:05 PM

"The influence of atmospheric pressure on the density of sea water and on the seabed would I think be so miniscule to be completely insignificant."

You might well be right, but then you could say the same about typhoons over land. Its just a hypothesis after all. I can't be arsed to trawl through the literature to find out more or what's changed since the paper's been published, so I'm out.

Also, despite the fact the paper is intriguing, none of this is as interesting as dinosaurs ;-)

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 22 Sep 17 - 02:15 PM

Stu you should have gone for micropaleo. That is a very sellable skill when the oil price is up.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 22 Sep 17 - 03:32 PM

Nah, dinosaurs for me. Can observe them in the real world every day.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 22 Sep 17 - 05:16 PM

But the thing is that your calculations relating to hydrostatic pressure, atmospheric pressure, etc., may well be correct but you are failing to connect them in any way to seismic activity deep down in the crust, "deep down" being where almost all severe earthquakes originate. All very interesting but ultimately worthless speculation unless you have evidence. Sorry to keep harping on about this, but studying it for years and coming up with imaginative ideas are NOT evidence, not in the remotest way.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 23 Sep 17 - 04:35 AM

Steve the discussion started with asking can hurricanes cause earthquakes. No stipulation that they should be big ones, little ones or that they should be bright blue and gift wrapped just for you.
You seem to have a fixation on plate boundary tectonics-we ain't talking about that. Not all faults are deep down in the crust, some may have their epicenter deep down but but others are much closer to surface. Why pontificate about a subject where your knowledge is woefully deficient?
The argument proposed by many of the papers I linked to suggests that many minor surcharges to a body in stress can in certain cases partially relax that stress,(an earthquake-big-little-indifferent) it does not have to be deep seated.
Possible mechanisms:
Heavy rain causing landslides
Heavy rain causing hydraulic loading in karst areas
Filling major reservoirs
Emptying reservoirs
The passage of an intense storm.

Mr Red's analogy 21 Sep 17 - 10:13 AM of the tap tap scenario is very plausible. especially for a storm system, tides accentuated, water ponded, vigorous wave action all create repetitive spikes above the normal background noise. Can this create earthquakes? A more demanding question may be: Why can it not? Extracting micro seismic events from background noise require accurate instrumentation, recording and analysis. I do not have first hand knowledge to elaborate on that
other than to say microseismic monitoring is used in the chalk reservoirs in the North Sea and for monitoring fracture orientation in the Bakken Shale
Food for thought

The tap tap tap scenario?
https://www.livescience.com/42495-model-suggests-earthquake-warning-signs.html

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 23 Sep 17 - 04:47 AM

Havn't you gone over to SI units yet Iains?

I bar (standard atmospheric pressure) = 750 torr.

1 torr is not significantly different from the old unit of pressure, the mm of mercury.

The density of mercury is 13.534 times that of fresh water.

Keith is right. I think he is also right in that the reduction of the sea level due to atmospheric pressure increases precisely cancels out this increase when calculating the pressure on the sea bed. The effect of atmospheric pressure changes on the sea bed is not just miniscule, it is zero.

Dinosaurs are a different matter. Having one of them wade through a shallow lagoon would definitely cause pressure changes, and may well trigger seismic activity.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 23 Sep 17 - 04:58 AM

The original post in this thread stated that Mexico city was prone to earthquakes. The reason for this is well known, it is that it sits close to a tectonic plate boundary. So it is quite resonable for people responding to the OP, who know a bit about the subject, to "have a fixation on plate boundary tectonics". And then to say "we ain't talking about that", well yes we are, because the subject is earthquakes, and all of the most destructive and deadly earthquakes are related to plate boundary tectonics.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 23 Sep 17 - 07:33 AM

Thanks, David.

Faults don't have epicentres, Iains, but earthquakes do. I haven't ruled out in my mind that surface variations may contribute to some seismic activity, but, unless you can provide direct evidence to the contrary (as opposed to speculation, interesting though it is), I'm sticking to my view that almost all non-trivial seismic events are caused by tectonic movements in the crust related to convection in the mantle. And do desist from your silly tendency to cast aspersions on other people's knowledge. There are times when you demonstrate that you're not always the sharpest knife in the drawer yourself.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 23 Sep 17 - 10:39 AM

Not every country or industry is compelled to use SI units.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 23 Sep 17 - 10:43 AM

Shaw I think I have provided plenty of examples but of course you do not open links do you. Perhaps this might explain your intransigence
on this and other threads I contribute to. Try reading a few links.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 23 Sep 17 - 11:09 AM

David Carter:Keith is right. I think he is also right in that the reduction of the sea level due to atmospheric pressure increases precisely cancels out this increase when calculating the pressure on the sea bed. The effect of atmospheric pressure changes on the sea bed is not just miniscule, it is zero.
What I said was:1)Therefore high pressure and low pressure systems modify the hydrostatic head of a column of seawater.
2)Low pressure can generate intense storms containing abundant energy leading to exaggerated tides,surges and wave action.
3)All these activities generate seismic noise.

Perfectly true as far as it goes. Now whether the atmospheric changes cancel out these hydrostatic changes instantaneously or if there is a time lag I have no idea and really is a non issue because in the deep ocean a change in hydrostatic head of 7psi would be negligible and although over dogger bank it may or may not have an impact it is the storm effects that are of significance. Increased wave action, increased tidal action, storm surges. Also some of these effects are accentuated by wind and direction, and the geometry of enclosed areas (N. Sea, Severn Estuary) There are numerous links on the web that support this. It is the storm that is significant, not the changes in atmospheric pressure.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 23 Sep 17 - 12:20 PM

I have to side with Teribus as to the insignificance of storms at sea influencing seismic events.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 23 Sep 17 - 01:40 PM

You last post has little or nothing to do with seismic events, Iains. It has everything to do with trying to show us that you can string together technical words and phrases regardless of whether they inform the discussion about earthquakes. As for links, yes I do open links. What I don't do is open links that are not commented on by the poster. In my view that is bad-mannered and dead lazy. I want to know what posters here think about whatever it is we're talking about. If you put up a link I want to know why you think it's relevant. I've opened too many rubbishy links here to waste any more time on unsupported ones. And I'm very unlikely to open links to the Mail or Telegraph. If you can, just tell us what you think. I know of one forum that won't accept unsupported links in posts at all.

It's sad that dictionaries now accept "miniscule." That usage displays ignorance of the etymology of the word. To me, its minuscule and always will be. Just a minuscule point there.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 23 Sep 17 - 04:57 PM

For Steve. Microseisms are the continuous background vibrations of the Earth observed between earthquakes and created by wave action in the deep ocean and reflection from the shoreline(in reality it is a complex interaction) To all intents and purposed it is disregarded as noise.
Storms over the oceans also represent major sources of microseismic activity. Research has suggested storms may be tracked by responses from geophone arrays, besides more conventional techniques. This would indicate that storm events can be discriminated from "noise" by their unique seismic signature. It would seem a not unreasonable assumption that in a stressed area a little nudge may be all that is needed to trigger an earthquake. Probably in most cases a very minor one, but nevertheless an earthquake. I do not dispute the fact that the major quakes occur at plate boundaries and major interplate quakes are rare beasts. But the fact that faults exist everywhere and that each represents at least one seismic event(or multiple events)would suggest to me that various mechanisms are at work. It is probably a fair argument that convection in the mantle is a major cause of stress in the crust all over any particular plate but the stress release mechanism can be any of a number of factors, some of which have already been mentioned.Also relaxation of stress does not have to be one big response, it could be a sequential series of small stress releases as with the idea of water injection on major faults to lubricate and hence cause failure at a much lower intensity and therefore less damaging. There is a body of research that does offer some support for these ideas but more research is needed to gain general acceptance. It is really not so much an idea of what causes the earthquake but more a consideration of potential triggers or repetitive events creating a trigger by exceeding thresholds. This is not really something that can be hammered out in a couple of paragraphs especially when everyone has a different starting point in their understanding. And at the end of the day everyone knows that a true geologist has spent at least three years working at every permutation of "perhaps" or "maybe". A straight yes or no with no qualification would be a disgrace to the profession.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 23 Sep 17 - 05:24 PM

Nice copy and paste. I agree with all of that. But the plain fact is that we know that major earthquakes are triggered by sudden movements of the crust very deep down, way below the influence, to any significant degree, of surface variations. Unless you have solid evidence to the contrary. All the links in the world, all the hypothesising, all the imaginative speculation, interesting though it all is (and it is), is not evidence.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 23 Sep 17 - 06:01 PM

I love the Bay of Naples and regard the area almost as the centre of civilisation. I've been there three or four times now. It has Vesuvius, Pompei, Herculaneum, Stabiae, Pliny the Elder, Naples with its amazing pizza and archeological museum, not to speak of St Gennaro's bones sticking out of an urn in the duomo, and the Campi Flegrei. The latter is the caldera that resulted from the Campanian Ignimbrite super-eruption 39000 years ago, the one that may have finally put paid to the Neanderthals. Vesuvius isn't actually part of that caldera. Every one of those places is an A1 stunner. One of the most intriguing places is the very workaday town of Pozzuoli. In the Roman macellum there are three columns that show evidence of erosion by marine molluscs from a time when the area was clearly inundated by the sea. These days the columns are way above sea level. The whole area is subject to the slow heaving and subsiding of the land (bradyseism) due to the movement of a large magma field not very far below the surface. In the early 1980s much of Pozzuoli underwent an uplift which raised the sea floor by two metres in a very short time. There was mucho panic and tens of thousands of people were evacuated. There was the fear that a huge super-eruption was imminent, but the crisis went away. We went to Pozzuoli in 2013 and walked up the hill from the Metropolitana station to the Solfatara crater (tragically, three people lost their lives there last month). It's the most lively place in the Campi Flegrei caldera, with sinister boiling mud pools and lots of hissing fumaroles. A thousand years ago there was a phreatic eruption (ground water interacting with magma), but it's been fairly quiet ever since. St Gennaro, him of the bones in the urn, was murdered there in the third century. Campi Flegrei is regarded as a potential supervolcano of the same ilk as Yellowstone. Go there before you die. Did the earth move for you?

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 23 Sep 17 - 06:27 PM

Beautiful tour Steve!

Iains I know the agony involved in giving an unqualified yes or no.
The more you know the harder it is.
Chaos theory claims a butterfly's flutter can set systems in motion to grow into a hurricane. Quantum systems may influence our own consciousness. It all depends on what scale we place the observer, not on being wrong or right.

When placed on the stand there comes a time when the lawyer asks you to respond yes or no and you must choose, although to do so, is incorrect and inaccurate.

Subject: Nuclear Weapons & Earthquakes - related?
From: Donuel
Date: 23 Sep 17 - 07:42 PM

Today a 3.4 earthquake with an epicenter precisely at North Korea's underground nuke test facility has been deemed a natural quake by US officials.

I think this way Trump won't feel like Kim stuck his thumb in Donald's eye again. Donald can call this a fake quake.

Also a 6.1 hit Mexico city again today.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: robomatic
Date: 23 Sep 17 - 08:52 PM

We are on a waiting list but not of our choosing. Since the Great Good Friday Earthquake of '64 we've been reaccumulating local underground stresses. We had a 7.1 about a year ago that did no real damage but is just a precursor. Can't say that we're a focal point of civilization, but then, that's a positive point for many of us.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 24 Sep 17 - 04:39 AM

"Not every country or industry is compelled to use SI units."

When presenting or discussing science you are though, otherwise you're not doing science.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 24 Sep 17 - 04:44 AM

MrShaw
"Nice copy and paste." Actually all my own work.I do have a slight familiarity with the subject matter.
Less severe earthquakes can occur for a variety of reasons already outlined. The evidence has already been presented. If you wish to discuss it fine. If you merely want to display your hubris go find another thread.
Other causes of earthquakes:
Dams
CO2
groundwater extraction
volcanoes
Geothermal well circulation


Donuel. Not every question can be answered adequately -Lawyers need to live in the real world too.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 24 Sep 17 - 04:56 AM

Stu
"Not every country or industry is compelled to use SI units."

When presenting or discussing science you are though, otherwise you're not doing science.
I suggest you take your grievance to the SPE or AAPG and chastise the oil industry

Units

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 24 Sep 17 - 11:00 AM

Your familiarity with the subject matter is indeed slight. Faults with epicentres indeed.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 24 Sep 17 - 06:06 PM

Apart from the Solfatara crater, the Campi Flegrei is a fairly unimpressive place to visit, it's true. The bulk of the caldera is under the sea, and much of the inland part is built up in a pretty nondescript way. As I said, Pozzuoli, the main town, is a very ordinary sort of place, hardly a tourist Mecca. Naples is a few miles away and is outside the Campi Flegrei caldera. I don't think that even a big eruption of Vesuvius would trouble Naples too much except to scare everyone to death. Earthquakes are a far greater threat. But the nearby caldera is a very lively place seismically and who knows what could happen. Four million people live in the metropolitan area of Naples. There is a massive evacuation plan in place should the planet turn angry. The trouble is, volcanic soils are so fertile, and the Bay of Naples is such a good place for ports and big industries. The fruit and the wine and the pasta (especially from Gragnano in the case of the pasta) are all as good as it gets. The San Marzano tomatoes are the best anywhere. Try the Lacryma Christi wines, grown in vineyards on the slopes of Vesuvio. And there's the pizza in Naples, the best in the world. I asked the man in a little pizzeria just across from the Archeological Museum for a pizza fritta. He gave me a knowing look, then, three minutes later, presented me with a deep-fried folded pizza at least four times as big as the biggest pasty I've ever seen. But I would not be beaten. I ate the lot. I didn't need food for the next 36 hours. We won't mention the Camorra. Just watch your pockets in Napoli, that's all. But looking across the bay from anywhere - so beautiful. You have the islands of Procida, Ischia and Capri, and standing at Marina Grande below Sorrento you see the whole bay with its islands, right across to Vesuvius with the conurbation of Naples at its foot, best seen at night. There's nowhere on the planet I'd rather be. Almost best of all, on the other side of the Sorrentine peninsula there's the Amalfi coast. Take my advice and let someone else drive you along the Amalfi coast road.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 24 Sep 17 - 06:26 PM

"Your familiarity with the subject matter is indeed slight". Ah but unlike you shaw I am quite happy to admit it. And I have spent the last 47 years as a professional geologist practising in several different fields, wearing several different hats. I do not claim papal infallibility, unlike your goodself. I have absolute confidence that I am not perfect and have not the slightest problem with admitting to a lack of detailed knowledge in certain areas of geology and a host of other subjects besides. But when it comes to seismic I have opened the toy box and used the data from some of the tools such as VSP and look ahead seismic, so I have sufficient knowledge to use the data in certain applications. I also do not require lectures on what units to use in scientific reports or papers. It is a case of horses for courses. The US is not fully using SI units yet, a common density unit is pounds per gallon in the oil industry. The most frequent geophysical log run in a well measures gamma rays. The units of measurement are API units running roughly from 0 in coal to 100+ in shales and the calibration is based on a bit of limestone sitting in Houston, I believe. Not an SI unit anywhere in sight. If you have a well control situation you really do not wanting to be having a conversation about why someone feels you should be using SI units. You need to be using the units that the oil company and rig crew are conversant with because when people screw up well control situations can easily escalate from kick to blow out. I have encountered many of the former and worked on relief wells for the latter. It does concentrate the mind and encourage you ensure everyone is singing the same toons on the same page, with the same language and same measurements even if it includes furlongs a fortnight.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 24 Sep 17 - 06:44 PM

Very unconvincing, and redolent of your sheer insecurity. 'Twas not I who brought up your shortcomings apropos of units. As I said before, you have this urgent need to show us how good you are at stringing together technical words and phrases. Well, you're on Mudcat now, a forum of non-specialists, and, if you really want to convince them of anything, you have to use coherent language understandable by the layperson.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 25 Sep 17 - 04:37 AM

No Shaw, I carefully explained above, summarising anything of the complexity of the subject raised in a couple of paragraphs is not going to hack it. I also said not everyone has the same starting point in terms of knowledge. If you keep on trying to fault everything I posit then obviously the discussion is going to Start to become a little more technical.
My particular interest is in borehole stability and how it is influenced by both regional stress and the mineralogy of clays. The latter being of particular difficulty because of their unique characteristics. Having looked at numerous failures(faults) in core boxes, in the field, and studied shear surfaces under the microscope I have a knowledge that is of both limited appeal and distribution. That is a fact of life. However it is in a way related to seismic activity as it is a study of rock failure.
If you feel it is too technical for mudcat you had ample opportunity to raise the issue earlier, or you could simply stop trying to create argument(your favourite tactic). Rock failure is a subject I have a deep interest in.
I see in one of your warblings about volcanoes you either swallowed wikipedia or you were out to impress A Level students of physical geography so I suspect you are equally guilty. The difference is that I am trying to give a simplified explanation whereas you are merely trying to demonstrate your superior erudition, as per usual.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 25 Sep 17 - 05:04 AM

Absence of evidence is not Evidence of absence.

With all random events there are contributory factors and not all factors will have been significant in any one instance.

What you are saying when you say there is no evidence is more accurately "statistically indeterminate" (your threshold)
But statistical answers depend on the question you ask. And by definition you are into philosophical territory. Ask a different question and you look at it differently. Blinkers off helps.

According to the New Scientist, there will be more Earthquakes because of Global Warming. And they report on such research. I am sure there are those of this parish that will refute that - please submit your thesis to them, first!

Seismic noise causes quakes, sometimes we call it "aftershocks". And we call it noise for a very, very, very good reason. Lack of evidence! Or the will to collect it more like.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 25 Sep 17 - 05:05 AM

My "warblings" were entirely predicated on my visits to the area and my sheer enthusiasm for it. It's interesting to hear that you specialise in boring. I think I could have spotted that earlier. Keep digging.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 25 Sep 17 - 05:26 AM

"I suggest you take your grievance to the SPE or AAPG and chastise the oil industry"

Interesting link, but that's not science as they are standards for a specific industry and are parochial ones at that; are mixed American units the standard in Europe? Were these matters being published in the literature they would be in SI units or wouldn't get through peer review.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 25 Sep 17 - 06:58 AM

The idea that global warming might trigger earthquakes in some regions is not ridiculous, the mechanism would be the reduction of the weight of the ice sheet above certain landmasses. Antarctica and Greenland in particular, but maybe also some mountain ranges. Most of the articles I can find on this go back to work by Bill McGuire of UCL, sometime director of the Benfield UCL Hazard Research Centre. It is also he and his students or postdocs (Simon Day and Stephen Ward) who are responsible for the idea that the Western side of La Palma might slide into the sea, causing a "megatsunami" which might devastate the eastern seaboard of North America.

Bill McGuire is a credible scientist, and his analysis of the impacts of various natural phenomena is usually pretty good. What often gets lost though when this research gets reported in the popular press is the incredibly low probabilities of these events.

As far as "absence of evidence is not evidence of absence", well if both evidence and a mechanism are absent then its pretty clear that its something which you don't have to worry about too much. Bill McGuire to be fair does propose mechanisms, and then when you understand what the mechanism is you can work out the probability of it occurring.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 25 Sep 17 - 07:23 AM

Stu The AAPG website guide for submission of papers:
"General rules

    Use metric units of measure with the English unit equivalent in parantheses or, CONVERSELY, ENGLISH UNITS WITH METRIC EQUIVALENTS IN PARENTHESES. Laboratory measurements do not require conversions.
   
No one would dispute the desirability of everyone converting and being familiar with SI units-But we are not there yet.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Stu
Date: 25 Sep 17 - 08:13 AM

"But we are not there yet.""

Most of us are.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 25 Sep 17 - 09:22 AM

David Carter. An interesting article from the Guardian from a year ago
concerning possible phenomena from a warming world. The headline is a little hysterical but the points raised are distinct possibilities.

https://www.theguardian.com/world/2016/oct/16/climate-change-triggers-earthquakes-tsunamis-volcanoes

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 25 Sep 17 - 09:26 AM

That link was an amplification of Bill Macguires work.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 25 Sep 17 - 02:10 PM

It's not only the headline that's hysterical. It's most of the article. Via unsupported assertions, he's blasting away centuries of accumulated scientific knowledge about whxt really triggers earthquakes and volcanoes, and he's ascribing causes to effects without evidence. As a flight of the imagination it's lovely. As science, well it isn't science as we know it.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Donuel
Date: 25 Sep 17 - 06:51 PM

Its not my balliwick. What the hell is a balliwick and why would I say that
anyway I've only been in two earthquakes.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 26 Sep 17 - 11:26 AM

"Via unsupported assertions, he's blasting away centuries of accumulated scientific knowledge about whxt really triggers earthquakes and volcanoes, and he's ascribing causes to effects without evidence"

I wonder to is the more correct shaw or professor Mcguire? my money is on the professor. After all his professional assertions have to withstand peer review, shaw only has to attempt to bully browbeat and argue mudcat BS posters.

A little background:Mcguire was a member of the UK Government's Natural Hazard Working Group, established by Prime Minister Tony Blair following the 2004 Indian Ocean tsunami. In 2010 he was member of the Scientific Advisory Group for Emergencies (SAGE), to address problems following the eruptions of Eyjafjallajökull. He contributed to the IPCC summary report on extreme weather and disasters (2011).

Seems you are outnumbered shaw by a few heavyweights.
They obviously think he has valid contributions to make. Now I would posit that he is a well educated scientist, not a poser who thinks he is!

]
Emeritus Prof Bill Mcguire Volcanologist

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 26 Sep 17 - 02:14 PM

Logical fallacy, appeal to authority.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 26 Sep 17 - 02:46 PM

According to NASA ADS, which I accept may not capture all geosciences articles, McGuire (W.J.) wrote one refereed paper in 2012, one in 2009, one in 2006, one in 2004, and quite a few before 2000. These are his publications which have to withstand peer-review, not op-ed pieces in the guardian. He was not a co-author with Day and Ward on the paper on Cumbre Vieja, though he comes up on TV programmes on the subject. I would be inclined to believe his assertions if they were made in these few peer-reviewed papers, not in the Guardian and not on TV. These papers are mostly on slope failure of volcanos, his most cited work was done at Mt. Etna in the late 80s and early 90s.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 26 Sep 17 - 06:29 PM

Well Mr McGuire is a man who makes his living out of being sensational. Like a stopped clock he may be right very occasionally. Real science is a far more prosaic and honest endeavour. Let's see if any of his disaster scenarios ever come true, shall we?

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 27 Sep 17 - 07:23 AM

Shaw the entire article in the guardian was summarising ideas from a number of people from a variety of institutions. To Say "Via unsupported assertions, he's blasting away centuries of accumulated scientific knowledge about whxt(SP, tsk) really triggers earthquakes and volcanoes,"is simply not true
I did qualify my ststement by saying his professional assertions have to withstand peer review and that the scenarios were very plausible.
brief history of seismology It is only in recent decades that advances in equipment, data acquisition, computing power and analysis has enabled detailed analysis to occur. His basic premise is that many triggers exist to initiate earthquakes.
As a poor analogy,if you are shot with a bullet, is it the focused release of energy contained within the cartridge that does the damage, or the pulling of the trigger, or the pointing of the gun? The fact the energy has accumulated is not disputed, just the mechanism of its release.
The body of evidence for human or weather induced triggers of seismic is ever growing.
USGS induced earthquakes
anthropogenic earthquakes
earthquakes by human activity
If human activities can cause earthquakes it should come as no surprise that many other potential triggers exist,as have been outlined. Earthquakes can cause slope failure-likewise slope failure can cause earthquakes.

Erosion can create earthquakes       ( a good set of references at the end)

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: keberoxu
Date: 29 Sep 17 - 08:10 PM

maybe the weather will please pretty please be
a little more peaceable.
Give the rest of us a chance to catch our breath here.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 29 Sep 17 - 08:32 PM

Sentiment appreciated, keberoxu. However. You know how it is. I repeat. Mr McGuire has made his living by being sensational. All you have to do is look at his book titles, then contemplate how life just rumbles on in the same old way. Iains gets himself over-excited by Daily Mail-style headlines, confirming his need for excitement by seeking out sources such as the overly-dramatic Mr McGuire's pennings. I mean, how many years/decades/centuries do we have to wait before Iains/McGuire is "proven right?" You and I will be well under the sod, I reckon. But who knows?

I suppose I have to repeat it: almost all earthquakes of any consequence whatsoever occur many kilometres under the surface, well away from surface influences. Still, you can't tell some people...

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 01 Oct 17 - 02:33 PM

David Carter.
Your fringe scientist.Bill Mcguire
Emeritus Professor of Earth Sciences

Courses Taught:
GEOLGH01 Geological & Geotechnical Hazards
GEOLGH02 Meteorological Hazards
GEOLGH06 Meteorological, Climate & Hydrogeological Hazards

A peer reviewed paper

Liggins, F., Betts, R.A., McGuire, W.J. (2010). Projected future climate changes in the context of geological and geomorphologic
and at the Geological society
https://www.geolsoc.org.uk/WakingTheGiant16
Low probability high impact events kill people equally as efficiently as high probablity high impact events.
The Storegga Slide for instance!

I do believe his peers feel he has valid points to make.
Also most areas of the world are now creating seismic hazard maps and many of these hazards are not " earthquakes of any consequence occuring many kilometres under the surface, well away from surface influences."
I do believe our resident botanist/exteacher owes Bill Mcguire an apology, after all papers in the Philosophical Transactions of the Royal Society can hardly be equated with the Daily Wail. Or perhaps in the world of the loony left, they can.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 01 Oct 17 - 04:42 PM

As a proud member of the loony left, I should like to apologise to Mr McGuire for the embarrassment being caused to him by Iains. In particular, I should like to apologise to Mr McGuire for the persistence with which Iains is using him as his source for his ongoing appeal to authority, that well-known logical fallacy. One tends to think that this resort is a clear indication of a person's inability to think for himself and to formulate constructive arguments. So sorry, Mr McGuire. I have tried, honest I have.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 02 Oct 17 - 04:35 AM

Shaw if you widened your research of the subject beyond wikipedia the discussion could no doubt progress.
As you seem unable to do this, there is no point in continuing the conversation, as we will constantly be at cross purposes.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 02 Oct 17 - 06:05 AM

Your first link doesn't work Iains. The second is to a lecture not a peer reviewed publication. However it is true that Bill McGuire published 6 papers in Philosophical Transactions of the Royal Society A, according to their own index, with the last few being in 2010. Philosophical Transactions of the Royal Society A appears not to be indexed by NASA ADS. So his output is roughly double what I had originally thought, but still nothing since 2012.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 02 Oct 17 - 06:24 AM

Ah, right,, those papers in 2010 are part of a theme issue, being the transcripts of papers at a colloquium at UCL the previous year. McGuire is one of the editors of the colloquium. It is not at all clear that they are peer-reviewed.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 02 Oct 17 - 06:42 AM

David Carter. Everyone has a right to retire. That is generally understood to be the meaning of the word emeritus. Perhaps the media
activity and writing provides an extremely useful pension supplement for the professor, after all he does have some internationally recognised expertise in his field/s
Retirement could also account for the dearth of papers in the recent past.

As an aside there are a number of universities in the UK running courses on disaster causes/risk management/call it what you will.
There is a growing realisation that Lyell's principle of Uniformitarianism ,of slow uniform change, is interspersed with infrequent shortlived periods of rapid change. of which earthquakes are one manifestation. The body of work suggesting an impact terminated the Cretaceous and the recorded impact of shoemaker levy on Jupiter has caused, in recent years, what might be termed a seismic change in attitude within the earth sciences.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Iains
Date: 02 Oct 17 - 07:00 AM

"It is not at all clear that they are peer-reviewed."

Peer review once held the earth was flat!

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Steve Shaw
Date: 02 Oct 17 - 07:21 AM

Earthquakes are extremely local events.

Lyell was influenced greatly by James Hutton, whose similar ideas came fifty years before Lyell's. Malcolm Rider's book Hutton's Arse, describing three billion years of geology in the northern Highlands of Scotland, is a cracking good read, plenty of good science and humour (and Malcolm hates wind turbines, which is fine by me!).

I suggest you stop making yourself look idiotic, Iains, by constantly deriding what you see as others' lack of knowledge in fields in which you yourself are clearly very shaky. If your scientific acumen was really as sound as you pretend it is, you wouldn't need to keep appealing to authority in your rather unfocused way.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: David Carter (UK)
Date: 02 Oct 17 - 09:52 AM

I know what an Emeritus Professor is Iains, I am one myself. I do not begrudge McGuire his right to write columns in the media, but if I were to do so myself I would not stray beyond work which had already withstood peer review. Now he may not have done so, it isn't possible always to access the full text of the peer reviewed papers, but what concerns me most is the time lapse between those papers and the newspaper articles.

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 05 Oct 17 - 04:36 PM

The current episode of BBC R4 "Inside Science" spends about 30% of its alloted 30 minutes on the subject of Human Induced Earthquakes" the biggest of which (alledged) is the 7.9 one in Wenchuan, 3 Km from the newly built and filled large dam. I think nature can outdo a lake.

They point to the the Human-Induced Earthquake Database that collates "peer-reviewed articles" for inclusion. Interestingly at physics.org they say:

"The more important trend is that between hydraulically fractured boreholes and unusually large earthquakes, most likely related to the reactivation of pre-existing geological faults."

Subject: RE: BS: Hurricanes & Earthquakes - related?
From: Mr Red
Date: 05 Oct 17 - 04:37 PM

reactivation sound a lot like threshold.