• journal_title：Geology
• Contributor：James G. Moore ; Richard A. Schweickert ; Joel E. Robinson ; Mary M. Lahren ; Christopher A. Kitts
• Publisher：Geological Society of America
• Date：2006-
• Format：text/html
• Language：en
• Identifier：10.1130/G22643A.1
• journal_abbrev：Geology
• issn：0091-7613
• volume：34
• issue：11
• firstpage：965

An array of east-trending ridges 1–2 m high and up to 2 km long occurs on the Tahoe City shelf, a submerged wave-cut bench <15 m deep in the northwest sector of the lake. The shelf is just north of the amphitheater of the giant subaqueous 10 km³ McKinney Bay landslide, which originated on the west wall of Lake Tahoe. Images from a submersible camera show that the ridges are composed of loose piles of boulders and cobbles that lie directly on poorly consolidated, fine-bedded lake beds deposited in an ancestral Lake Tahoe. Dredge hauls from landslide distal blocks, as well as from the walls of the re-entrant of the landslide, recovered similar lake sediments. The McKinney Bay landslide generated strong currents, which rearranged previous glacial-derived debris into giant ripples creating the boulder ridges. The uncollapsed part of the sediment bench, including the Tahoe City shelf, poses a hazard because it may fail again, producing a landslide and damaging waves.