2002-2003 Science Planning Summary

Geology & Geophysics

Dr. Scott Borg
Program Manager

GO-085-O

NSF/OPP 01-26269
Station: McMurdo Station
RPSC POC: Mike McClanahan
Research Site(s): Mt. Erebus

U-Series (uranium-series) isotopic constraints on the rates of magma genesis evolution and degassing at Mt. Erebus, Antarctica
Dr. Kenneth W. Sims
Woods Hole Oceanographic Institute
Department of Geology and Geophysics
ksims@whoi.edu

Deploying Team Members: See Phil Kyle (GO-081-)
Research Objectives: Mount Erebus, Ross Island is the most active volcano in Antarctica. It is unique in containing a persistent convecting lava lake of anorthoclase phonolite magma. Degassing of the lake and underlying magmatic system emits volcanic gases into the pristine Antarctic atmosphere. Because of the good access and the nature of the small strombolian eruptions, Erebus has become a model volcano for volcanological studies. In the 2002-2003 field season, three separate funded projects will be undertaken at Mt. Erebus. All three projects will work as an integrated team. Some of the objectives of the three projects are:

-To collect volcanic rocks samples and gases and measure U-decay series isotopes in them to assemble a geochemical-isotopic-petrologic data set to evaluate the rate dependent parameters of magma genesis, evolution and degassing

-To deploy five integrated surveillance instrumentation (ISI) systems containing a broadband seismometer, dual frequency GPS receiver, tiltmeter, a variety of environmental sensors and associated power systems (batteries, solar panels and wind generators)

-To continue the annual surveillance of the volcanic activity as part of the Mt. Erebus Volcano Observatory studies.

The existing short period and new broadband seismic network will allow an understanding of the eruptive behavior and dynamics of Mt. Erebus. Inversion of the seismic data will allow topographic imaging of the magma chamber and plumbing inside the volcano. Collected data will be used to evaluate the potential impact of gas emission from Erebus on the snow chemistry on the East Antarctic Ice Sheet. Researchers will also examine short-term variations in the emission rates of F, Cl, SO2 and metals to examine volatile zoning in the magma chamber supplying the lava lake. A GPS network on the flanks and summit of the volcano will be re-occupied to examine any deformation that may have occurred. (NSF Award # 0126269)


Field Season Overview:
Project team members will work closely with Phil Kyle (GO-081-O) to maximize logistical resources. Project team members will establish a camp at the Lower Erebus Hut and will use it as a base of operations for work on and around Mt. Erebus. With helicopter and snowmobile support they will collect gas and lava samples to study uranium series isotopes.

Once a week, samples will be sent by helicopter to McMurdo Station. From there they will be forwarded to a laboratory in France for further analysis.