التفاصيل البيبلوغرافية
| العنوان: |
The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR |
| المؤلفون: |
Chadwick, William W Jr, Jonsson, Sigurjon, Geist, Dennis J., Poland, Michael P., Johnson, Daniel J., Batt, Spencer, Harpp, Karen S., Ruiz, Andrés Gorki |
| المساهمون: |
Crustal Deformation and InSAR Group, Earth Science and Engineering Program, Environmental Science and Engineering Program, Physical Sciences and Engineering (PSE) Division, Oregon State University/NOAA, Hatfield Marine Science Center, Newport, OR 97365, United States, Department of Geological Sciences, University of Idaho, Moscow, ID 83844, United States, Hawaiian Volcano Observatory, USGS, Volcano, HI 96718, United States, Department of Geology, University of Puget Sound, Tacoma, WA 98416, United States, Department of Geology, Colgate University, Hamilton, NY 13346, United States, Instituto Geofísico, Escuela Politécnica Nacional, Quito, Ecuador |
| بيانات النشر: |
Springer Nature |
| سنة النشر: |
2010 |
| مصطلحات موضوعية: |
Circumferential dike intrusion, Ground deformation, Kinematic modeling, Magma reservoirs, geo, envir |
| الوصف: |
The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45-60°) toward the caldera at the surface and more gently dipping (~12-14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another. © 2010 Springer-Verlag. ; The manuscript was greatly improved by helpful reviews from Sang-Ho Yun and Scott ... |
| نوع الوثيقة: |
article in journal/newspaper |
| اللغة: |
unknown |
| Relation: |
http://hdl.handle.net/10754/561642 |
| الاتاحة: |
http://hdl.handle.net/10754/561642 |
| Rights: |
undefined |
| رقم الانضمام: |
edsbas.A6D68F6A |
| قاعدة البيانات: |
BASE |