Va. well reacts to Haiti quake; aftershocks continue
The US. Geological Survey continues to monitor seismic events in Haiti in the wake of last evening's terrible 7.0 quake just outside the capital of Port-au-Prince. At last check, the country had sustained at least 34 aftershocks of magnitude 4.5 to 5.9.
Other faults in the region have also been active. There was a magnitude 2.5 tremor early today in the Mona Passage between Hispaniola and Puerto Rico. And the Virgin Islands reported a 3.2 shake late last night.
The powerful quake in Haiti registered strongly in a water well in Christiansburg, in southwestern Virginia, operated by the Va. Department of Environmental Quality and monitored by the USGS.
The well is very sensitive to seismic waves passing through the Earth, and water levels will rise and fall sharply in response to large quakes around the world. Here (below) is the tracing of the well's water levels in the past few days. The Haiti quake is reflected in the sharp spike - more than 9 inches - on Jan. 12.
USGS officials in Baltimore said they have seen no similar response to the quake in water wells monitored in Maryland or Delaware. (No word from dog owners. Here's how one pooch reacted seconds BEFORE the recent quake off the Northern California coast.)
Comments
If the spike was not registered in other ground water sites across the region how do we know for sure that this wasn't a data aberration unrelated to the Haiti quake? Just curious!
FR: Because this well is known to be especially sensitive to seismic waves, and has shown similar spikes in the past after large quakes around the world. The timing of the spikes confirms that they occur in response to the arrival of seismic waves passing through the Earth's crust at known speeds. Here is a link to more seismic responses by this well. The Haiti event is not yet posted. http://bit.ly/8csrV5
Sometimes other wells in the region will show a response to such events, but not as reliably as this one. The Christiansburg well also shows a regular rise and fall (you can see it in the tracing) in response to the tidal forces of the moon as they're transmitted through the Earth.
Posted by: Peter Corrigan | January 13, 2010 1:26 PM