The origin of Mauna Loa's Nīnole Hills: Evidence of rift zone reorganization

Geophysical Research Letters
By: , and 

Links

Abstract

In order to identify the origin of Mauna Loa volcano's Nīnole Hills, Bouguer gravity was used to delineate density contrasts within the edifice. Our survey identified two residual anomalies beneath the Southwest Rift Zone (SWRZ) and the Nīnole Hills. The Nīnole Hills anomaly is elongated, striking northeast, and in inversions both anomalies merge at approximately −7 km above sea level. The positive anomaly, modeled as a rock volume of ~1200 km3 beneath the Nīnole Hills, is associated with old eruptive vents. Based on the geologic and geophysical data, we propose that the gravity anomaly under the Nīnole Hills records an early SWRZ orientation, now abandoned due to geologically rapid rift-zone reorganization. Catastrophic submarine landslides from Mauna Loa's western flank are the most likely cause for the concurrent abandonment of the Nīnole Hills section of the SWRZ. Rift zone reorganization induced by mass wasting is likely more common than currently recognized.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The origin of Mauna Loa's Nīnole Hills: Evidence of rift zone reorganization
Series title Geophysical Research Letters
DOI 10.1002/2015GL065863
Volume 42
Issue 20
Year Published 2015
Language English
Publisher American Geophysical Union
Contributing office(s) Volcano Science Center
Description 9 p.
First page 8358
Last page 8366
Country United States
State Hawaii
Other Geospatial Mauna Loa, Nīnole Hills