Hawaii's Mauna Loa volcano currently presents a window of scientific opportunity that is unprecedented. Recent geodetic evidence shows that Earth's largest volcano has begun to re-inflate and is likely in the first stage of a typical eruption cycle comprising: 1) summit inflation, 2) summit eruption, and 3) dike propagation and flank eruptions. Although more than 30 such eruptive cycles have occurred here since 1833, and one as recently as the 10 years prior to the 1984 eruption, the accompanying surface deformation fields have never been analyzed with data from the new generation of high-resolution space- based geodetic platforms that is currently revolutionizing volcano geodesy.
We propose to investigate the kinematics and mechanics of crustal deformation and its relation to magmatic processes at Mauna Loa by comparing GPS- and InSAR-derived surface displacement fields and time series with predictions from numerical simulations designed to simulate gravitational loading conditions. We will install 12 continuously operating GPS (CGPS) and 30 survey GPS (SGPS) stations focused on Mauna Loa's rift zones and flanks. We will combine the GPS data with an InSAR-derived time series from ENVISAT repeat passes to provide spatial continuity at a pixel spacing of 10s of meters over areas greater than 10s of kilometers.
The investigation of three fundamental volcanotectonic processes and related questions drive our investigation:
1) Summit Inflation and Eruption. What is the spatial location and geometry of the summit magma chamber and how does it change prior, and leading up, to a summit eruption? What are the mechanical boundary conditions throughout the edifice in which a summit eruption occurs?
2) Dike Propagation and Flank Eruption. What is the relationship between summit and rift zone intrusions/flank eruptions? What controls the dynamics of dike propagation down a flank rift zone? A particularly exciting prospect is that the CGPS sites will capture major dike-intrusion events into one of Mauna Loa's flanking rift zones.
3) Gravitational Volcanic Deformation. How do topographically-induced stresses influence near-surface deformation and volcanic processes? How do neighboring volcanoes, such as Kilauea, impact volcanotectonic phenomena?
