From that link,

"The map below (taken from my thesis) shows the different naming influences on settlements in Britain. The most striking aspect is the abrupt end to the Viking settlement names along what is called the Danelaw Line. So if you live north of this line you will be using more Viking words on a daily basis than those to the south. There are loads of people studying and recording the different place naming conventions in Britain- I would recommend you check out the "Institute for Name Studies" if you want more information."

Plenty to keep you busy in those links.

~ Becky in Long Beach