NWT RESEARCH DATABASE

Tags: physical sciences, geology, seismology, tectonic movement

Objective(s): To study the deep geologic structure of the earths mantle; and to study plate tectonics and processess that create mountains.

Project Description: This project consists of a large deployment of ground motion sensors (290 total) throughout Alaska and western Canada; 44 located in Yukon Territory and 9 in the Northwest Territory. Each station senses the ground movement from distant earthquakes and sends data via satellite or radio modem to a central receiving point in San Diego. The purpose of collecting these data is to study deep geologic structure of the earth, dynamics of tectonic motion, earthquake hazard, as well as induced seismicity related to human activity (disposal wells and carbon sequestration). This project images the deep structure of the earth, from depths of about 5km to the core of the earth but is primarily tuned to study the structure of the mantle (50-600 km beneath the surface) and to study plate tectonics and processes that create mountains. The instruments are spread too far apart (85km) to provide detailed imaging commonly used for exploration for oil and gas (whose drills go less than 4km deep)- though the technique applied is similar. Further science objectives and rationale are explained in a 63 page report http://www.iris.edu/hq/Aiaska_Workshop_2011/report.php. Site reviews and reconnaissance began in 2013, with the first specific locations chosen. Deployment of stations would began in 2014, proceed slowly and be complete in 2016 or 2017. The stations are temporary and would be removed in 2019-2020. Some stations may be selected by Canadian agencies for longer term monitoring needs. Each station has a 20cm diameter sensor embedded in the ground from 1-5m deep, depending on soil conditions, and a nearby hut (1.2mx1.2m x2m) containing solar power, batteries, and electronics. Additional scientific data for weather, air pressure, soil temperature are also collected. At this time, no soil sampling is planned. The data is relayed immediately to USGS and NRCan government agencies for earthquake location and emergency alerts. Data are also and used by university researchers throughout Canada and the United States, indeed worldwide. Data are freely available and open to anyone. Views of the data are made available through the Internet in real-time. Different displays of the data that are geared towards public, education and science users are created by IRIS and also made available through the Internet. Additional research studies using these data are carried out by the general scientific community. IRIS will provide a summary of the work we have completed as well as significant findings from outside studies. The fieldwork for this study will be conducted from February 29, 2016 to December 31, 2016.