Replacement processor for EdgeTech sub-bottom echosounder

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This proposal seeks funding to upgrade an existing heavily used EdgeTech echosounder that is now obsolete. Echo sounders are an important geophysical tool in lake studies. By using sound waves transmitted through the water column they provide high resolution sub bottom profiles of the stratigraphy, thickness and geometry of sediments below lake (or sea) floors which contain records of environmental change. Such sediments also may contain structural disturbances that record ancient earthquakes. Most earthquakes occur at the margins of large tectonic plates. One of the most active areas in Canada straddles the Ontario-Quebec border; the Western Quebec Seismic Zone and includes Montreal and Ottawa extending south to New York. Recent work investigating the floor of lakes Timiskaming and Kipawa along the Ontario/Quebec border reveals ongoing faulting of lakefloor sediments and slumps triggered by seismic shaking such as the large (M6.2) Timiskaming Earthquake in 1935. The potential for a large damaging earthquake requires evaluation of earthquake frequency using echosounder equipment to image the floors of hundreds of lakes. Mapping the geographic distribution of disturbances from lake to lake will identify the areal extent of ground shaking and thus earthquake epicenters and magnitudes; essential data for risk management assessment. Around the Great Lakes, the sediment layers below the floors of shallow lagoons contain a rich history of watershed evolution after European settlement around 1800 and recent urbanization. Echosounding from small boats or on lake ice can constrain sedimentological history, identifies key sites for coring, detailed chemical analysis and allow assessment of impacts on biota over the last 200 years.