Ring faults, partially buried by alluvial fans and landslides, limit the caldera in the lake. A large landslide forms Glinyany Peninsula in the southeastern shore of the lake. Post-caldera activity has formed some islands in the lake and the Diky Greben volcano. Both Glinyany Peninsula and the post-caldera lava domes (Chayachii, Serdtze Alaida, Tugumynk) were affected by slumping. Approximately of sediment and volcanites bury the deposits left in the caldera by the caldera-forming eruption.