HVO Fieldwork #2

We ventured down into the Kilauea caldera with gas masks at the ready to undertake a kinematic gps survey. Andy Pitty and I did the gps while Ingrid and Mike Poland went ahead to do a gravity survey. The halema'uma'u vent (above) has been active since March 2008 so the area we were working in is off limits to the public.

Unlike the static GPS units mentioned in my previous post, these units are designed for mobility. The survey involves taking readings at set benchmarks along a survey line in the caldera. Any small changes in the position of the benchmarks give indications of deformation which could preceed an eruptive phase.

A gravity survey was also conducted. These expensive and incredibly sensitive devices measure the torque on a metal spring attached to a weight to measure local gravity anomalies. These anomalies could indicate movement of magma beneath the surface.

images courtesy of USGS