HR: 1330h
AN: V22C-0597    [PDF]
TI: Transient Deformation Following the January 30, 1997 Dike Intrusion at Kilauea Volcano, Hawaii
AU: * Desmarais, E K
EM: emilyd@stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305 United States
AU: Segall, P
EM: segall@pangea.stanford.edu
AF: Stanford University, Department of Geophysics 397 Panama Mall, Stanford, CA 94305 United States
AB: On 30 January 1997 a new fissure opened within the East Rift Zone (ERZ) of Kilauea Volcano at Napau Crater, 3km uprift from the ongoing eruptions at Pu'u O'o. The fissure eruption lasted for two days and opened a nearly vertical dike 1.96m wide by 5.15km long that extended from the surface to a depth of 2.4km (Owen et al., GRL, 1997). During the fissure eruption, the lava pond at Pu'u O'o drained pausing the eruptions there for nearly a month until it eventually refilled in late February; eruptions there resumed on 28 March 1997. The Kilauea Volcano permanent GPS network recorded the eruption and a significant transient following the dike intrusion in the ERZ. In the 120 days following the event the closest station to the fissure, KTPM, moved an additional 7 cm to the south. We invert continuous and campaign GPS data using an extended Network Inversion Filter (McGuire and Segall, in press, Geophys. J. Int.) for the time dependent volume change of a Mogi source under Kilauea's summit, opening of a nearly vertical dike in the ERZ and slip on a decollement under the south flank. The extended filter allows simultaneous estimation of slip rate with temporal smoothing, spatial smoothing, positivity, random walk and data error scale parameters resulting in improved spatial and temporal resolution over previous filters (Segall et al., EOS Mtg. Abs., 1998). This study models post eruptive deformation as the crust accommodates the opening of the dike to gain understanding about the relaxation time of the Hawaiian crust and the potential for catastrophic failure of the south flank of Kilauea Volcano. Preliminary results show that most dike opening is accommodated in the top 2-3 km of with maximum velocity around 15 cm/day. Every model shows Mogi source under Kilauea rapidly inflating after months of gradual pre-fissure eruption deflation. The decollement slips gradually seaward during the first month after the eruption.
DE: 0684 Transient and time domain
DE: 1208 Crustal movements--intraplate (8110)
DE: 1243 Space geodetic surveys
DE: 8145 Physics of magma and magma bodies
DE: 8419 Eruption monitoring (7280)
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting