The geodetic community has brought a new array of technological innovations, powerful new analytical tools, and integrative geological and geophysical modeling to address a range of fundamental scientific questions related to magmatic systems. Recent research has helped quantify the distribution of strain across Iceland’s Western and Eastern Volcanic Zones, which accommodate North America/Eurasia plate motion in southern Iceland, and correlate it with zones of active magmatism. Surface deformation measurements and microearthquake data on the Kilauea volcanic edifice have revealed how magmatic and topographic stresses control the occurrence of slow slip events and magmatic activity associated with the large-scale collapse of the edifice. New networks of GPS instruments and InSAR observations in Lake Tahoe, Hawaii, the Philippines, the Galapagos, the Pacific Northwest, and the Afar depression have helped characterize magmatic plumbing systems and their temporal and spatial evolution. Intensive field observations have captured the details of deformation associated with major eruptions at Mount St. Helens, Augustine, Sierra Negra and Fernandina volcanoes (Galapagos), Tungurahua (Ecuador), Kilauea, and Stromboli (Italy), providing valuable information about the eruptive process.
A remarkable suite of geodetic, geophysical, and geologic data from the Yellowstone caldera has helped provide new constraints on the location, geometry, and temporal changes in the magmatic sources driving deformation beneath an active silicic caldera system. GPS monitoring of the caldera now extends over two decades and has recorded four distinct phases of caldera uplift and subsidence, most recently capturing a remarkable stage of caldera uplift, with rates up to 60 mm/year. The project has also clarified possible interaction between the Yellowstone system and long-term viscoelastic post-seismic deformation following the 1956 M7.5 Hebgen Lake earthquake.
For her PhD thesis, Christine Puskas integrated PBO Global Positioning System (GPS) data with other observations to create a snapshot of annual surface motion due to faulting and volcanic deformation in and around the Yellowstone caldera (figure 2). In 2004, the caldera began to uplift and subside without accompanying earthquakes due to the accumulation and migration of fluids derived from a magma reservoir that is tens of kilometers deep. Puskas' work revealed the contributions of volcanic forces, fault and plate boundary motions, and the gravitational force of high-standing mountain ranges to the GPS-determined regional deformation. Puskas and Smith (2009)
Figure 1 - Unpublished image, see similar images in: Amelung, F.,S-H. Yun, T.R. Walter, P. Segall and S.W. Kim, Stress control of deep rift intrusion at Mauna Loa volcano, Hawaii. Science 316: 1026-1030 [DOI: 10.1126/science.1140035], 2007. More information is available here.
Figure 2 - Puskas, C.M., 2009, Contemporary deformation, kinematics, and dynamics of the Yellowstone hotspot and western U.S. interior from GPS, fault slip rates, and earthquake data: Salt Lake City, University of Utah, 238 p. Puskas, C.M., and Smith, R.B., in press, Intraplate deformation and microplate tectonics of the Yellowstone hotspot and surrounding western U.S. interior: Journal of Geophysical Research.
Last modified: Monday, 03-Aug-2015 19:28:29 UTC