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Table of Contents - Special Paper 386

Reconstruction of Pleistocene Ice-Dammed Lake Outburst Floods in the Altai Mountains, Siberia

Edited by Jürgen Herget

Abstract			1
Chapter 1. Introduction
Problems			3
Aims			3
Methods			4
Structure of the Study			4
Chapter 2. Ice-Dammed Lakes and Jökulhlaups
2.1 Classification of Ice-Dammed Lakes			7
2.2 Mode of Drainage and Outburst Mechanisms			8
2,3 Hydrographs of Jökulhlaups			9
2.4 Occurrence and Distribution			9
Chapter 3. Altai Mountains
3.1 Location and Geology			13
3.2 Current Climate			15
3.3 Quaternary of Altai Mountains			16
Chapter 4. Evidence of Jökulhlaups in the Altai Mountains
4.1 Previous Studies and Reviews			19
4.2 Flood-Related Features			22
	4.2.1 Lake Sediments and Shorelines		22
	4.2.2 Ice Dam and Failure Mechanism		24
	4.2.3 Giant Bars and Indication of Flow Conditions		27
	4.2.4 Secondary Lakes		34
	4.2.5 Gravel Dunes		35
	4.2.6 Erosional Forms		37
	4.2.7 Boulder Deposits		38
4.3 Criticism on Occurrence of Jökulhlaups in the Altai Mountains			38
4.4 Open Questions			39
Chapter 5. Reconstruction of the Floods
5.1 Uniform Flow Calculation			41
	5.1.1 Introduction		41
	5.1.2 Hydraulic Background		41
	5.1.3 Data from the Altai Mountains		42
	5.1.4 Paleohydraulic Calculations		42
	5.1.5 Discussion		44
5.2 Flow Calculation by HEC-RAS			44
	5.2.1 Introduction		44
	5.2.2 Hydraulics		45
	5.2.3 Paleostage Indicators		46
	5.2.4 Paleohydraulic Calculation		47
		5.2.4.1 Previous water level calculations of Pleistocene outburst floods	47
		5.2.4.2 Previous water profile calculations for the flood in the Altai Mountains	49
		5.2.4.3 Calculations for mixed flow regime	53
	5.2.5 Discussion		56
5.3 Velocity Head Calculations using Run-Up Sediments			57
	5.3.1 Introduction		57
	5.3.2 Hydraulics		57
	5.3.3 Run-Up Sediments in Chuja and Katun Valley		58
	5.3.4 Paleohydraulic Calculation		59
	5.3.5 Discussion		61
5.4 Correlation of Lake Volume and Peak Discharge			62
	5.4.1 Introduction		62
	5.4.2 Hydraulics		66
	5.4.3 Volume of Ice-Dammed Lake		67
	5.4.4 Paleohydraulic Calculation		67
	5.4.5 Discussion		67
5.5 Boulder Transport			68
	5.5.1 Introduction		68
	5.5.2 Hydraulic Background		68
	5.5.3 Boulders near Inja Village		71
	5.5.4 Paleohydraulic Calculations		71
	5.5.5 Discussion		72
5.6 Gravel dunes			73
	5.6.1 Introduction		73
	5.6.2 Hydraulic Background		73
	5.6.3 Dune Data for Paleohydraulic Reconstruction		76
	5.6.4 Paleohydraulic Calculations		82
	5.6.5 Discussion		86
5.7 Obstacle marks			86
	5.7.1 Introduction		86
	5.7.2 Hydraulic Background		88
		5.7.2.1 Submerged obstacles	88
		5.7.2.2 Bridge piers	88
	5.7.3 Examples of Obstacle Marks in Chuja and Katun Valleys		92
	5.7.3 Paleohydraulic Calculations		97
	5.7.3 Discussion		100
Chapter 6. Review of Dynamics of the Altai Jökulhlaups			101
Acknowledgments			103
Appendices
Table A1. Location and Characteristics of Flood Features			104
Table A2. Bar Surfaces and Levels from Topographic Maps			110
References Cited			111