Figure 1.

Catastrophic lake drainage and lacustrine delta formation. (A) Approximate location of the five thermokarst lakes analyzed herein. (B) Planet CubeSat imagery of two thermokarst lakes (Lake ID 99492) showing images before (L1f) and after (L1d) drainage, where lake L1 rapidly drained into lake L2 (L2f). (C) Satellite imagery showing L1 drainage through a preexisting channel (T1: 27 Sept. 2017) that evolved into a thermo-erosion gulley (T2: 7 June 2018). This event eroded, transported, and deposited large volumes of sediment and remobilized soil organic carbon (SOC) into the delta in L2 (T3: 11 July 2020). (D) Schematic model of L1 drainage, creation of a thermo-erosion gulley, and deposition of a delta in L2. AK—Alaska.