Archive for November, 2012

Magnitude 6.4 – 248km S of Cape Yakataga, Alaska – November 12, 2012

November 14, 2012

Location:  57.605°N   -142.899°W

Depth=12km (7.5mi)

Theoretical P wave arrival to BC-ESP sites:  20:50:35.7 UTC time

For more info on this earthquake, go to US Geological Survey report.

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Magnitude 7.4 – 35KM S OF CHAMPERICO, GUATEMALA – NOVEMBER 7, 2012

November 14, 2012

Location:  13.987°N  -91.965°W

Depth=24.1km (15mi)

P wave arrival to BC-ESP sites:  16:42:24.6 UTC time

For more info on this earthquake, go to US Geological Survey report.

Hurricane Sandy Recorded by Seismographs: Interdependency and Interrelationships Within the Earth System

November 3, 2012

Seismology provides an interesting window into the interdependency and interrelationships within the Earth System.

The seismograms of Hurricane Sandy shown below were recorded by the Boston College Educational Seismology Project (BC-ESP) on our BC campus seismograph. This is a good example of seismology as a window into the interdependency and interrelationships within the Earth System. Hurricane winds and waves generate seismic waves that are recorded by seismographs. And by coincidence, this is not only a fascinating recording of an historic hurricane, but it happens to also include one of the most well-recorded earthquakes I have ever seen on our educational seismographs. Plus, we just happened to record aftershocks of that well-recorded quake on the same seismogram as the main shock.

And, if you look very carefully near the beginning of the October 30 seismogram, you can see a magnitude 6.2 aftershock “hiding” beneath the hurricane waves.