To make our subsidence measurements, we have traveled to Bangladesh to install, maintain, and repair our equipment. These include continuously recording GNSS systems (i.e., GPS), mostly installed on the roofs of buildings. Many of these are co-located with surface elevation tables (SETs) in conjunction with Louisiana State University. We independently surveyed geodetic monuments and investigated the sinking of historic sites. We also operated a optical fiber strainmeter measuring sediment compaction across six depth intervals until the instrument was destroyed by riverbank erosion. Detailed descriptions of our fieldwork are available on the Columbia University Climate school blog, State of the Planet: Geohazards of Bangladesh.
