Manitouwadge, Schreiber, Longlac and White River among 16 New Seismometer Locations

Written by admin on 05 June 2011

Manitouwadge Airport. Photo OntarioNewsNorth.com 2010

MANITOUWADGE, ON – Geoscientists from five American and Canadian universities are installing a series of seismometers in Minnesota, Wisconsin, and Ontario as a part of the SPREE (Superior Province Rifting EarthScope Experiment) Project.These seismometers will record earthquakes that occur locally,regionally, and throughout the world. Scientists use the seismic waves from these earthquakes to produce high-resolution images of the Earth’s interior.

The earthquake monitoring equipment, was placed at the Manitouwadge Municipal Airport May 30th and will remain in place for approximately 2.5 years. This same equipment has also been installed near other Northshore Greenstone communities inclunding:

White River (installed May 29)
Hornepayne (installed May 30)
Chapleau (installed June 1)
Schrieber – June 3
Beardmore – June 3
Longlac – June 4
Lake Superior Provincial Park (one in the north, one in the south; installed June 3)

Superior Province Rifting Earthscope Experiment (SPREE) is funded by National Science Foundation (NSF) and carried out by three U.S. and two Canadian universities. The purpose is to investigate the structure of the North American continent and the physical processes controlling earthquakes and volcanic eruptions.

Seismometer solar panels. Photo from earth.northwestern.edu

Though earthquakes are rare in the middle of a continent the equipment is being placed there to study a geologic feature called the Midcontinent Rift. About a billion years ago, this part of the continent started to break apart, or “rift”. Over about 20 million years, an enormous amount of volcanic rock was erupted or intruded into the crust.In total, the Midcontinent Rift contains about 1.5 million cubic kilometers of igneous volcanic rock—enough to fill up all of the Great Lakes 66 and a half times!

Many rifts break continents apart to form new oceans. That’s what happened when Europe and North America rifted apart to form the Atlantic Ocean. But here, despite its size, the Midcontinent Rift failed to break apart the continent.

Scientists don’t know why some rifts succeed, and others fail. The subsurface structure of the Midcontinent Rift is still relatively unknown. We’ll use the data recorded by the seismometers to create images of the rift’s structure deep below the surface—like taking a CAT scan or an ultrasound of the Earth. Studying the structure of the rift will provide clues about why it started, how it grew, and why it failed.

The seismic stations will remain in place for about two and a half years. Sixteen stations in Ontario are scattered around the northern part of Lake Superior. In Minnesota and Wisconsin, two lines of stations cross the rift and two lines follow the rift for a total of 67 stations. Each station is placed in an area far from sources of noise and vibration such as roads, railroads, and occupied buildings.

This project is funded by EarthScope (www.earthscope.org) and represents a collaboration between Northwestern University, Washington University in St. Louis, the University of Minnesota, the University of Manitoba, and the University of Quebec at Montreal.