2016-2017 USAP Field Season
Magma sources, residence and pathways of Mount Erebus phonolitic volcano, Antarctica, from magnetotelluric resistivity structure
Dr. Philip Wannamaker
University of Utah
Supporting Stations: McMurdo Station
This event, in collaboration with Dr. Graham Hill of Gateway Antarctica/University of Canterbury deploying under Antarctica New Zealand (ANZ) project number K-108, will collect approximately 125 magnetotelluric (MT) soundings during the course of three field seasons over the active phonolitic volcano Mt Erebus and Ross Island. Analysis of these data will yield a 3D tomographic model of electrical resistivity through the crust and into the uppermost mantle. This physical property will provide inferences on location of the upper-middle crustal magma chamber implied from petrology, the staging volume of parental melts near Moho levels, and the magma/volatile conduit through the crust and volcanic edifice. Two field seasons have already taken place. The first season, carried out within the Antarctica New Zealand program, was completed in 2014-15. The second season in 2015-16 was completed under joint USAP/ANZ support staged out of Scott Base. These two seasons yielded 95 high-quality sites including the reference. International collaborators providing essential instrumentation include Yasuo Ogawa of Tokyo Institute of Technology (TITECH) and Martyn Unsworth of University of Alberta.
Field Season Overview
This project will work together with K-108 (Hill) of ANZ to collect at least 24 new MT soundings at select locations over Ross Island to fill holes in previously recorded coverage. The entire team will be based in McMurdo instead of Scott Base. Wannamaker, Hill, and a mountaineer will start the season; Paul Bedrosian will arrive in December to replace Wannamaker. Clothing and other equipment will be issued by the USAP. ANZ personnel will assist with transporting all G-072-M/K-108 items stored at Scott Base over the winter to McMurdo.
Helicopter will be the mode of transport to almost all sounding sites, although two nearer McMurdo are accessible overland. Transport to those sites via AntNZ Hägglund still needs to be reviewed/approved. Helicopter hours will be provided by both AntNZ and USAP. For USAP helicopter support, night flights will be utilized as frequently as possible. At each site, about two hours are needed for a team of three (including the mountaineer) to set up the MT recording components. The site needs to record for at least 48 hours (assuming favorable weather) before take-down in preparation for the next deployment. However, typical weather experienced in the last two seasons has driven recording intervals of several days before a return is possible. Take down typically requires approximately 45 minutes. The group plans on two installations per day under favorable logistics. The helicopter may shut down in close support of a site, or it may leave for other work.
A reference recorder located off the trail to Room with a View must be checked approximately once per week; AntNZ has agreed to provide snowmobiles on Sundays for this trip. Participants must attend AntNZ snowmobile training prior. In the event that AntNZ cannot provide snowmobiles, the USAP can provide pooled snowmobiles; participants will need to attend USAP snowmobile training prior to use.
National Geographic will be based at Scott Base again this season and will likely want to accompany the team. The NSF has approved similar filming restrictions as last season, including but not limited to: (1) a cameraman can accompany the team in the field as long as additional helicopter support is not required to do so, and (2) filming should be field-based only.
Deploying Team Members