Alaska TA Sensor Emplacement: Overview and Applications in Collaborating Networks
Abstract
EarthScope's Alaska Transportable Array (TA) is now a fully installed network of 280 stations in Alaska and Canada-sponsored by the National Science Foundation and operated by the IRIS Consortium. During the deployment phase, IRIS developed sensor emplacement techniques suited for posthole style Broadband Seismometers and the remote environment. The techniques, now well honed, are efficient and effective in more typical land based seismic network installations. While completing the Alaska TA deployment, IRIS collaborated with regional network operators and government agencies, including the Alaska Earthquake Center (AEC), Alaska Volcano Observatory (AVO), Yukon Geological Survey, and Canadian Hazards Information Service to upgrade 27 existing seismic stations of the overall 81 cooperative stations contributing to Alaska TA.
IRIS continues to work closely with others to expand this technique to a variety of stations. In 2018, IRIS has completed seven borehole upgrades at stations operated by AVO, AEC, and Natural Resources Canada and helped construct the first Canadian Cordillera Array (CCArray) station at Kluane Lake Research Station, near Haines Junction YT. An additional 16 borehole upgrades and new installations are in progress or expected for the remainder of the 2018. These include borehole sensor emplacement at existing AEC stations in SE Alaska and additional test station installations at the Albuquerque Seismological Lab. We hope to apply similar posthole techniques to help repair seismic networks in Puerto Rico and perform additional emplacements in Canada's Yellowknife Array. We present an overview of the sensor emplacement techniques and procedures as developed by IRIS during the course of the TA deployment in AK at more than 200 stations and review the motivation and adaptation appropriate to non-TA station construction. Specifically, these advancements included utilizing a lightweight drilling system developed specifically for the TA project to be portable via helicopter, fixed wing, or truck. As well as the details of orientation, grouting and downhole sensor bedding and wellcap completion. These refinements of sensor emplacement technique improve data quality, uniformity and station reliability.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.S43E0669E
- Keywords:
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- 7294 Seismic instruments and networks;
- SEISMOLOGY