Saturday, February 13, 2010

Infragravity

clipped from wattsupwiththat.com

The researchers used seismic data collected on the Ross Ice Shelf to identify signals generated by infragravity waves that originated along the Northern California and British Columbia coasts, and modeled how much stress an ice shelf suffers in response to infragravity wave impacts. Bromirski said only recently has technology advanced to allow scientists to deploy seismometers for the extended periods on the ice shelf needed to capture such signals.

The study found that each of the Wilkins Ice Shelf breakup events in 2008 coincided with the estimated arrival of infragravity waves. The authors note that such waves could affect ice shelf stability by opening crevasses, reducing ice integrity through fracturing and initiating a collapse. “(Infragravity waves) may produce ice-shelf fractures that enable abrupt disintegration of ice shelves that are also affected by strong surface melting,” the authors note in the paper.