Early last Friday morning before sunrise a small slump occurred on a steep cleared slope about 20km from here, which I noticed while riding past on my bicycle. I obtained images on Tuesday, the images used here were mostly taken from 50-60m AGL, with about 100 taken from 25-30m, concentrated around the slump.
A few decades ago I’d noticed the signs of a previous slump (slight bulge to the right of this slump, with black dots on DTM), and when the owner had some earthmoving done to create a flat area just above it 3 or 4 years ago, I figured it was only a matter of time before another slump occurred.
Lots of rain the past 2 1/2 years, following the worst recorded drought lasting 2 years immediately before that, and particularly 140mm in September, got things moving. Apparently there was a slight amount of movement on the Thursday afternoon, but most of the movement was early on Friday 30th September.
531 images 19:24:08
|Options:|auto-boundary: true, dem-resolution: 2, dsm: true, dtm: true, mesh-octree-depth: 12, mesh-size: 300000, orthophoto-resolution: 1, pc-quality: high, pc-rectify: true, resize-to: -1, use-3dmesh: true|
|Average GSD:|1.29 cm|
Some earth moved downslope on the right hand side of the DTM, mostly eroded and accumulated at the bottom, rather than slumping.