A cautionary tale of topography and tilt from Kilauea Caldera

Geophysical Research Letters
By: , and 

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Abstract

We conduct finite element analysis to investigate the effect of sharp topography on surface ground deformation caused by pressure changes in a magma reservoir. Tilt data express the horizontal gradient of vertical displacement and therefore can emphasize small variations in deformation that go unnoticed using other methods. We find that the vertical displacement profile at a surface with a cliff can be thought of as the superposition of the deformation from shallow and deeper sources. This combination can create a small peak in vertical displacement that acts as a pseudo‐source, creating a reversal of the deformation gradient and therefore anomalous tilt magnitude and a rotation of up to 180°. We apply these models to Kīlauea Caldera and find that surface geometry creates a tilt rotation of ∼10°, partially explaining anomalous tilt that has been observed. Our analysis highlights the importance of considering topography when assessing tilt measurements at active volcanoes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A cautionary tale of topography and tilt from Kilauea Caldera
Series title Geophysical Research Letters
DOI 10.1029/2018GL081757
Volume 46
Issue 8
Year Published 2019
Language English
Publisher Wiley
Contributing office(s) Volcano Science Center
Description 9 p.
First page 4221
Last page 4229
Country United States
State Hawaii
Other Geospatial Kilauea Caldera