Thread: IRIS-PASSCAL (SAGE) Magnetotelluric Facility – Summer 2020 Update

The Incorporated Research Institutions for Seismology (IRIS) is making
steady progress towards establishing a new, comprehensive
magnetotelluric (MT) capability for the NSF-SAGE
https://www.iris.edu/hq/news/story/nsf_makes_5_year_93m_award_to_iris_to_manage_the_sage_facility
facility at the PASSCAL Instrument Center (PIC). Despite additional
challenges due to the ongoing pandemic, we have established the capacity
to test and evaluate MT instrumentation. This includes beginning to
procure a dozen portable long-period magnetotelluric (MT) systems
(LEMI-424), which will be available to Principal Investigators (PIs)
starting in 2021. The LEMIs include a datalogger and three-component
fluxgate magnetometer which are light-weight, low-power, and simple to
deploy and operate. In addition, we are in the midst of completing the
selection process for electric-field sensors (electrodes) and will
procure an initial batch of electrodes this summer.

We encourage U.S. Principal Investigators (PIs) and international
collaborators to consider these long-period MT systems and electrodes in
ongoing or planned experiments that have compatible science goals and
logistical flexibility. These types of MT instruments are typically
operated for up to several weeks to provide crust to lithosphere-scale
observations that complement common seismic analyses (receiver
functions, body-wave travel time, surface wave, and ambient-noise
tomography). PASSCAL Instrumentation is available to U.S. PIs free of
charge, under the standard instrument usage agreement
https://www.passcal.nmt.edu/content/general-information/policy/instrument-use-policy
for portable geophysical instruments and can be reserved through PASSCAL
Instrument Center (PIC) scheduling system https://www.passcal.nmt.edu/sdb.

IRIS also plans to procure an initial set of 2-3 wideband/broadband MT
systems by the end of 2020 and to continue this procurement in 2021 and
2022. PIs should propose experiments and make instrument requests based
on their projected needs. IRIS and the USGS are also working with the
community to draft a set of MT data and metadata standards and develop
open-source tools for processing MT data. A request for comment on
metadata standards was recently sent to this forum.

Finally, the pool of long-period NIMS MT instruments purchased under
EarthScope remain part of the SAGE MT facility but are on extended loan
to Oregon State University, which has partnered with the USGS to
complete the MT surveying of the contiguous U.S.
https://www.iris.edu/hq/programs/magnetotelluric_arrays that began
under EarthScope. This community dataset will be available through the
IRIS DMC. The status of the NIMS will be reevaluated in 2023.

More information on the PASSCAL MT facility is available through IRIS
https://www.iris.edu/hq/programs/passcal/magnetotelluric_instrumentation.

Any inquiries may be sent to IRIS MT Program Manager Andy Frassetto
(andy.frassetto AT iris.edu) and EMAC chair Ninfa Bennington (ninfa AT
geology.wisc.edu).

--
Andy Frassetto, PhD, Seismologist
MT Program Manager
Incorporated Research Institutions for Seismology