Using LIDAR to Track Changes in Lava and Ice

As an active volcano, Mount Erebus and the surrounding region are constantly changing. The lava lake in the Erebus main crater, as well as the ice towers and ice caves created by its volcanic gasses, change in depth, shape, and size on scales from days to years. These changes are being tracked season to season and day to day using LIDAR technology by New Mexico Tech Masters Student Laura Jones. Laura and LIDAR Guys technician Jed Frechette took me out on several days of LIDAR work, from ice caves to crater rim.

LIDAR, or LIght Detection And Ranging, is an optical remote sensing technology similar to RADAR that can be used to scan a region and create a three-dimensional computer map. Laura Jones is using an Optech Ilris 3D LIDAR system, which can achieve centimeter-scale resolution at distances of several hundred meters. That means that, even perched atop the crater rim, Laura can point her LIDAR at the Erebus lava lake (some 350 meters away) and return extremely high-resolution, high-density data.

With the scans that Laura has taken over two seasons on Erebus, she has been able to compare the data and see how the lava lake and ice towers change with time. What she has concluded is that, not only has the lava lake changed dramatically in shape, but it has actually dropped in depth by tens of meters. In addition to these observations, time series data (several scans taken in a short period of time) have allowed Laura to track the rise and fall of the lava lake that seems to happen in several minute cycles, possibly coinciding with magma convection within the lake.

Source: Science Friday