More Earthquakes
Another earthquake occurred in Sumatra, Indonesia. 70 are dead so far in mostly rural areas. It measured 6.3 on the Richter scale with a 6.1 after shock. It is not unusual in that area because of a nearby volcano. Seismic activity and earthquake swarms are expected in hot spots and near volcanoes. But is it just me or are there any awfully lot of them happening anymore? Just as suspected, a new and very recent study found that earthquake swarms are not necessarily clustered around volcanoes and in geothermal regions. They are occurring everywhere and anywhere there is seismic activity. Michigan is not excluded. I remember a pretty good tremor in 1978. I lived at Charlotte Arms and was home in the afternoon when I thought someone either overshot their parking space and hit the building or someone dropped something awfully large while moving. The building shook. It wasn’t until later I learned it was an earthquake. There is some pretty interesting history about Michigan earthquakes at http://earthquake.usgs.gov/regional/states/michigan/history.php. There were quite a few about 120 years ago that continued through the turn of the century.
As far as an increasing number of earthquakes, researchers gathered data from at least 40 earthquakes that did not follow the usual pattern of major shock followed by waves of small shocks or outbursts. According to a researcher “We saw a mix of the two kinds of events, swarms or earthquakes and aftershocks, wherever we looked. It confirms what people have suspected. There are earthquake swarms and they are responses to factors we can’t see and don’t have a direct way to measure.” http://www.sciencedaily.com/releases/2006/10/061025184753.htm.
So earthquakes are another occurrence within our environment that is increasing but we don’t know why and caused by what. We know our pollution is affecting weather above the ground. What about the earth’s surface heating up more? I’ve wondered about that. The jet stream air currents bend and bow according to El Nino and El Nina which are created and directly affected by surface water temperature heating up in the Atlantic, so what about surface land temperature? Does global warming affect the frequency of earthquakes by heating up land surface also? It will be interesting to see in the very near future the answers to these questions as our world struggles to change how we interact with and have a little more reverence for the environment that sustains us.