Earthquake Frequency


When the mile thick ice sheets of the last ice age melted 10,000 years ago, there were earthquakes that followed the melting, but recent melting is small potatoes. Consider that the ice age melt raised the sea level about 100 meters, but we recently in the last century have had a sea level rise of only about 0.3 meters, with a likely 1 meter rise in the next 100 years

I don't consider it a significant worry, except that the fossil fuel advocates use the story to ridicule those of us who want to reduce caron emissions.

Here is a scientific basis from 3 years ago:

Melting Ice Sheets Can Cause Earthquakes, Study Finds Mason Inman
for National Geographic News

March 14, 2008
As ice sheets melt, they can release pent-up energy and trigger massive earthquakes, according to new study.

Global warming may already be triggering such earthquakes and may cause more in the future as ice continues to melt worldwide, the researchers say.

A series of large earthquakes shook Scandinavia around 10,000 years ago, along faults that are now quiet, the scientists point out.

The timing of each earthquake roughly coincided with the melting of thick ice sheets from the last ice age in those same places.

Researchers had suspected that the melting had triggered these earthquakes by releasing pressure that had built up in Earth's crust.

Now a new study, the first to use sophisticated computer models to simulate how ice sheets would affect the crust in the region, bolsters this scenario.

The study showed that earthquakes are "suppressed in presence of the ice and promoted during melting of the ice," said study leader Andrea Hampel of the Ruhr University Bochum in Germany.

Hampel and a colleague had earlier found evidence that the shrinkage of a huge lake at the end of the last ice age had triggered a series of large earthquakes in Utah.

The new study shows this can happen even along faults that are normally quiet and are not prone to slip.

The new research will be published soon in the journal Earth and Planetary Science Letters
http://news.nationalgeographic.com/news/2008/03/080314-warming-quakes.html

Bob

 

My own study of the United States Geological Survey Statistics is reproduced below.

 

I just counted the earthquakes of magnitude 7 and over in each year and found that 2010 was a record year with 22 earthquakes. This said the numbers are very random and while this short period shows an upward trend it is probably not unprecedented in recent times.

 

 

 

The above article would suggest that I am looking in the wrong place for climate related earthquakes. I should perhaps be looking for smaller earthquakes in usually stable regions.

 

Extracted Data

 

Malcolm