thumbnail

Reconnaissance map showing thickness of volcanic ash deposits in the greater Hilo area, Hawaii

Miscellaneous Field Studies Map 1499

By:

Links

Abstract

This study was undertaken to determine the thickness and distribution of volcanic ash deposits in the greater Hilo area, Hawaii, as a step toward evaluating their susceptibility to failure during earthquake shaking. On several occasions their instability has resulted in serious damage. For example, the 1868 earthquake (m=7+), following a prolonged rainy period, caused a debris flow of hillside ash deposits that killed 31 people in Wood Valley (Bringham, 1869). The 1973 Honomu earthquake (m=6.2) resulted in more damage from shaking to areas underlain by ash deposits in the older part of Hilo than in other areas, and soil slips in ash, as well as rockfalls, were common along the roads north of town (Nielsen and others, 1977). 

Three geologic units are represented on the accompanying map: the ash deposits, a clay bed that locally underlies the ash, and the bedrock material. 

Study Area

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Reconnaissance map showing thickness of volcanic ash deposits in the greater Hilo area, Hawaii
Series title:
Miscellaneous Field Studies Map
Series number:
1499
Year Published:
1983
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Description:
28.40 x 28.25 inches
Country:
United States
State:
Hawai'i
City:
Hilo
Scale:
24000
Online Only (Y/N):
N
Additional Online Files (Y/N):
N