Magmatically Triggered Slow Slip at Kilauea Volcano, Hawaii
Benjamin A. Brooks,1
James Foster,1
David Sandwell,2
Cecily J. Wolfe,1
Paul Okubo,3
Michael Poland,3
David Myer2
We demonstrate that a recent dike intrusion probably triggered
a slow fault-slip event (SSE) on Kilauea volcano's mobile south
flank. Our analysis combined models of Advanced Land Observing
Satellite interferometric dike-intrusion displacement maps with
continuous Global Positioning System (GPS) displacement vectors
to show that deformation nearly identical to four previous SSEs
at Kilauea occurred at far-field sites shortly after the intrusion.
We model stress changes because of both secular deformation
and the intrusion and find that both would increase the Coulomb
failure stress on possible SSE slip surfaces by roughly the
same amount. These results, in concert with the observation
that none of the previous SSEs at Kilauea was directly preceded
by intrusions but rather occurred during times of normal background
deformation, suggest that both extrinsic (intrusion-triggering)
and intrinsic (secular fault creep) fault processes can lead
to SSEs.
2 Scripps Institution of Oceanography, La Jolla, CA 92093–0225, USA.
3 Hawaiian Volcano Observatory, U.S. Geological Survey, Hawaii National Park, HI 96718, USA.
