Megafloods Six Really Big Events You Should Know About (in addition to the one you may remember!) 1 Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 Types of Glacial Megafloods • Sea Inundation • Glacial Lake Outburst Flood • Ice dam floated • Moraine dam breached • Barrier overtopped & eroded • Jökulhlaup Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 2 Water, Water Everywhere! Inundation of Sundaland Inundation of Black Sea Glacial Lake Agassiz Glacial Lake Missoula Lake Bonneville Altai Glacial Lake Floods Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 3 Eden in the East Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 4 Mesopotamia Inundated Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 5 Mesopotamia Inundated Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 6 Black Sea Inundation Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 7 Glacial Lake Agassiz Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 8 Agassiz Phases Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 9 Agassiz Phases Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 10 Agassiz Ojibway 9,000 ybp Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 11 The Final Breakout 8,400 ybp Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 12 Siberian Altai Flood Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 13 Evidence: Ripples Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 14 Evidence: Terraces Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 15 Altai Flood Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 16 Altai Flood Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 17 Lake Bonneville Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 18 Water, Water Everywhere! Volume Max Flow Area Depth Flood km3 m3 km3 m Sundaland 600,000 52 15-13.5 kabp 10 kabp + 1,700,000 + 60 7,700 610 L. Missoula 2,184 3-16 x 106 15-13 kabp lake area (ice dam) 155,000 80 m Black Sea 10,000? 463,000 7,600 ybp flooded increase L. Agassiz >20,000 0.5 x 106 440,000 2-4 m MSL 11,335 ybp 6 8,400 ybp >40,000 5 x 10 lake area rise 1,500 650 Altai 600 10 x 106 12-9 kabp lake area (ice dam) 5,000 83,000 300 L. Bonneville 930,000 14,500 ybp initial breach max before 105 initial drop Tyler B Thompson MidMichigan Rock Club Tuesday, April 7, 2015 19.