|
Descripción
|
|
|---|---|
| Interdisciplinary space- and ground-based monitoring systems allowed the quantitative and detailed study of the Nyamulagira 2010 eruption (Congo). Field observations revealed the event as 4 eruptive phases delimited by major changes in effusive activity. Signals from ground deformation, seismicity, SO2 emission and thermal flux correlate with these eruptive phases. Moreover, MSBAS InSAR time series combining data acquired under different geometries and with different satellites (Samsonov and d?Oreye, 2012) allowed the detection of pre-, co- and inter-eruptive deformation in the Nyamulagira volcanic field. Using 8 years of ENVISAT, RADARSAT2 and ALOS data, the MSBAS method reveals the first unambiguous pre-eruptive ground deformations in the Virunga Volcanic Province. Precursory ground deformations are detected up to 3 weeks prior the onset of the 2010 eruption by images acquired by 3 different sensors in different geometries. These deformations took place in the main crater and along the SE flank of the volcano, where eruptive fractures will ultimately opened. Deformations coincide with small, though clear, increase of the short period seismicity and SO2 emissions.These seismic and SO2 variations alone were too small, however, to raise attention. The pre-eruptive ground deformation signals revealed by InSAR are of about the same amplitude and spatial extent as atmospheric noise and therefore cannot be identified on individual differential interferograms. Conventional time-series methods based on single acquisition geometry do not have a sufficient time resolution to discriminate such a precursory signal from an atmospheric artifact. The 3-week precursors detected at Nyamulagira contrast with the only precursory signal previously recognized so far in the Virunga, namely the increase of tremors and long period seismicity no more than few hours or days before the eruption onset. In January 2010, such short-term seismic precursors were detected less than two hours prior the eruption. Providing that enough SAR data is available with a short latency, and with the help of automated processing and trend change detection algorithms, the MSBAS method opens new opportunities for very high-resolution ground deformation studies and possibly for contributing to interdisciplinary volcano early warning systems. | |
|
Internacional
|
Si |
|
Nombre congreso
|
American Geophysical Union, Fall Meeting 2013 |
|
Tipo de participación
|
960 |
|
Lugar del congreso
|
San Francisco, CA |
|
Revisores
|
Si |
|
ISBN o ISSN
|
2324-9250 |
|
DOI
|
|
|
Fecha inicio congreso
|
09/12/2013 |
|
Fecha fin congreso
|
13/12/2013 |
|
Desde la página
|
1 |
|
Hasta la página
|
2 |
|
Título de las actas
|
AGU Fall Meeting Abstract V43B-2868 presented at 2013 Fall Meeting, AGU, San Francisco, Calif., 9-13 Dec |