EarthScope USArray Station C40A

EarthScope’s USArray Transportable Array of Seismometers – C40A

Station C40A, a seismic monitoring station, was in place on Isle Royale nearly two years from Sept 28, 2011 to Sept 18, 2013. The station consisted of an underground vault containing a seismometer, battery, a computer and communication equipment; and above ground elements including solar panels, an antenna, and a GPS receiver. The seismometer simultaneously recorded the earth’s motion in the vertical and horizontal directions.

The station at Isle Royale (TA Seismic Station C40A ) is one of the 2000 USArray seismic stations installed across the country as part of the National Science Foundation's EarthScope initiative. The USArray Transportable Array is an Earthquake monitoring system, operated and maintained by IRIS, (a non-profit corporation of US Universities) on behalf of the National Science Foundation.

Scientists are analyzing the data that was recorded at this station and across the country to learn how earthquakes are initiated and to gain a better understanding of the deep earth's dynamic structure and processes.

While on Isle Royale, TA Seismic Station C40A:

  • detected 191 regional earthquakes initiated less than 1100 km (approximately 684miles) from the station.

One regional event on 10/19/2011 detected by C40A was initiated in the Upper Peninsula of Michigan approximately 200 km (about 125 miles) from the station. It had a magnitude of 2.4. The first seismic waves (P waves) arrived at the Isle Royale station 32.4 seconds after the event occurred. The wave travelled through the earth’s crust at approximately 14,000 miles/hour.

  • detected 861 distant earthquakes (occurring more than 1100 km from the station).

On 5/24/2013, a distant event taking place in the Sea of Okhotsk, Russia, roughly 7100 km from the recording station (about 4400 miles), registered at a magnitude of 8.3. The first seismic waves arrived at the station on Isle Royale approximately 9 minutes after the event occurred. (P. Dorr, personal communication, August 6, 2015)

  • The magnitudes of the earthquakes registered ranged from very small (magnitude < 2.0) which are not felt by humans anywhere, to large events elsewhere in the word, which could have resulted in significant destruction.

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Sources: Earthscope Seismic Recording Station TA_C40A Summary Report, generated at the Array Network Facility (ANF) on Mon, 02 Feb 2015 20:08:48 UTC; Form version 2.0

Last updated: September 27, 2017