Skip to Main Content
Book Chapter

Downstream aggradation owing to lava dome extrusion and rainfall runoff at Volcán Santiaguito, Guatemala

By
Andrew J.L. Harris
Andrew J.L. Harris
Hawaii Institute of Geophysics and Planetology, School of Oceanography and Earth Science Technology, University of Hawai'i, 2525 Correa Road, Honolulu, Hawaii 96822, USA
Search for other works by this author on:
James W. Vallance
James W. Vallance
Cascades Volcano Observatory, U.S. Geological Survey, 1300 SE Cardinal Court, Building 10, Suite 100, Vancouver, Washington 98683, USA
Search for other works by this author on:
Paul Kimberly
Paul Kimberly
Smithsonian Institution, Department of Mineral Sciences, Washington, D.C. 20560-0119, USA
Search for other works by this author on:
William I. Rose
William I. Rose
Department of Geological Engineering and Sciences, Michigan Technological University, Houghton, Michigan 49931, USA
Search for other works by this author on:
Otoniel Matías
Otoniel Matías
Instituto Nacional de Sismología, Vulcanología, Meterología y Hidrología (INSIVUMEH), 7a Av. 14-57, Zona 13, Guatemala City, Guatemala
Search for other works by this author on:
Elly Bunzendahl
Elly Bunzendahl
Department of Geological Engineering and Sciences, Michigan Technological University, Houghton, Michigan 49931, USA
Search for other works by this author on:
Luke P. Flynn
Luke P. Flynn
Hawaii Institute of Geophysics and Planetology, School of Oceanography and Earth Science Technology, University of Hawai'i, 2525 Correa Road, Honolulu, Hawaii 96822, USA
Search for other works by this author on:
Harold Garbeil
Harold Garbeil
Hawaii Institute of Geophysics and Planetology, School of Oceanography and Earth Science Technology, University of Hawai'i, 2525 Correa Road, Honolulu, Hawaii 96822, USA
Search for other works by this author on:
Published:
January 01, 2006

Persistent lava extrusion at the Santiaguito dome complex (Guatemala) results in continuous lahar activity and river bed aggradation downstream of the volcano. We present a simple method that uses vegetation indices extracted from Landsat Thematic Mapper (TM) data to map impacted zones. Application of this technique to a time series of 21 TM images acquired between 1987 and 2000 allow us to map, measure, and track temporal and spatial variations in the area of lahar impact and river aggradation.

In the proximal zone of the fluvial system, these data show a positive correlation between extrusion rate at Santiaguito (E), aggradation area 12 months later (Aprox), and rainfall during the intervening 12 months (Rain12): Aprox = 3.92 + 0.50 E + 0.31 ln(Rain12) (r2= 0.79). This describes a situation in which an increase in sediment supply (extrusion rate) and/or a means to mobilize this sediment (rainfall) results in an increase in lahar activity (aggraded area). Across the medial zone, we find a positive correlation between extrusion rate and/or area of proximal aggradation and medial aggradation area (Amed): Amed = 18.84 - 0.05 Aprox - 6.15 Rain12 (r2 = 0.85). Here the correlation between rainfall and aggradation area is negative. This describes a situation in which increased sediment supply results in an increase in lahar activity but, because it is the zone of transport, an increase in rainfall serves to increase the transport efficiency of rivers flowing through this zone. Thus, increased rainfall flushes the medial zone of sediment.

These quantitative data allow us to empirically define the links between sediment supply and mobilization in this fluvial system and to derive predictive relationships that use rainfall and extrusion rates to estimate aggradation area 12 months hence.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

Volcanic Hazards in Central America

William I. Rose
William I. Rose
Search for other works by this author on:
Gregg J.S. Bluth
Gregg J.S. Bluth
Search for other works by this author on:
Michael J. Carr
Michael J. Carr
Search for other works by this author on:
John W. Ewert
John W. Ewert
Search for other works by this author on:
Lina C. Patino
Lina C. Patino
Search for other works by this author on:
James W. Vallance
James W. Vallance
Search for other works by this author on:
Geological Society of America
Volume
412
ISBN print:
9780813724126
Publication date:
January 01, 2006

References

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal