Imaging Magma Under St. Helens

The plan was to install up to ten stations using a test configuration consisting of two ZEN wideband MT receivers per station, with one ZEN equipped with long-period fluxgate magnetometers, and the other with high frequency induction coil magnetometers. The two receivers operate concurrently, for a target run length of at least one day, with designated sites operating longer, to obtain deeper information into the upper mantle, and to provide a “remote reference” for the other sites. This enables us to use “remote reference” processing procedures to improve data quality, particularly in the long-period MT “Dead Band” near 1 Hz, where there is lower natural signal level. By operating both long-period and high-frequency sensors concurrently, we can evaluate the relative performance of each, confirm inter-sensor calibrations, and generally test our deployment approach prior to staging the full field program in the coming weeks and months.

Some sample photos from the first week's work. Photos by Esteban Bowles-Martinez and Brady Fry.

A nice day to walk in the woods... getting ready to do some digging.

OK, time to start digging.

Laying out the array.

The Mount St. Helens area sometimes has spectacular views.