BS: Hurricanes & Earthquakes - related?

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

reactivation sound a lot like threshold.

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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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 - 02:14 PM

Logical fallacy, appeal to authority.

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: 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: 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: Iains
Date: 25 Sep 17 - 09:26 AM

That link was an amplification of Bill Macguires work.

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: 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 - 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: 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: 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: 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: 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: 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: 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: 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 - 06:06 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: 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: 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: 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: 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: 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: 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: 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: 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: 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: 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 - 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: 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: 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: 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 - 10:39 AM

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

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: 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: 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.