REPORT:
Hydrologic Consequences of Hot-Rock/Snowpack Interactions at Mount St. Helens Volcano, Washington, 1982-1984

Table of Contents

• Introduction
  -- by: Thomas C. Pierson and Richard B. Waitt
  • Background
  • Types of hot-rock/snowpack interactions
  • Processes of explosive eruptions
  • Processes of lava-dome mass failures
  • Types and characteristics of sediment-water flows
  • Volcanic activity and research at Mount St. Helens
  • Acknowledgments
  • References cited

• Nature of Depositional Contacts between Pyroclastic Deposits and Snow or Ice
  -- by: Joseph S. Walder
  • Abstract
  • Introduction
  • Heat-transfer considerations and illustrative experiments
  • Implications of theoretical and experimental results for interpretation of field observations
  • Conclusions
  • Acknowledgments
  • References cited

• Transformation of Water Flood to Debris Flow following the Eruption-Triggered Transient-Lake Breakout from the Crater on March 19, 1982
  -- by: Thomas C. Pierson
  • Abstract
  • Introduction
  • Lake-breakout flood
  • Flow transformation of the flood
  • Continued erosion and bulking by debris flow
  • Factors for transformation to debris flow
  • Summary and conclusions
  • Acknowledgments
  • References cited

• Sediment Transport in the Hyperconcentrated Phase of the March 19, 1982, Lahar
  -- by: Randal L. Dinehart
  • Abstract
  • Introduction
  • Flow characteristics observed at gaging stations
  • Analyses of sediment-transport measurements
  • Comparison of lahar with storm flow
  • Prediction and measurement of lahar behavior
  • Summary
  • References cited

• Dome-Collapse Rockslide and Multiple Sediment-Water Flows Generated by a Small Explosive Eruption on February 2-3, 1983
  -- by: Thomas C. Pierson and Richard B. Waitt
  • Abstract
  • The eruption of February 2-3, 1983
  • Volcanic processes affecting snowpack
  • Flows mobilized by pyroclast-snow interactions
  • Sequence and timing of flows
  • Source and effects of meltwater
  • Similarity to events of March 19, 1982
  • Mixed avalanche initiation mechanisms
  • Summary
  • References

• Rock Avalanches, Rockfalls, and Associated Processes Induced by Spreading of the Lava Dome, March 1984
  -- by Jon J. Major and Patrick T. Pringle
  • Abstract
  • Introduction
  • Timing of rock avalanches and rockfalls
  • Deposits of the rock avalanche-rockfall complex
  • Causes of rock avalanches and rockfalls
  • Implications for future mass failures
  • Conclusions
  • Acknowledgments
  • References cited

• Eruption-Triggered Lahar on May 14, 1984
  -- by Patrick T. Pringle and Kenneth A. Cameron
  • Abstract
  • Introduction
  • Eyewitness observations on May 14
  • Lahar deposits
  • Estimated deposit volume, water content, and heat energy implications
  • Velocity and discharge
  • Discussion
  • Summary
  • Acknowledgments
  • References cited

• Appendixes

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