T51G-3010
Deep Magma Accumulation at Nyamulagira Volcano in 2011 Detected by GNSS Observations
Friday, 18 December 2015
Poster Hall (Moscone South)
Kang Hyeun Ji1, Sarah Stamps2, Halldor Geirsson3, Niche Mashagiro4, Muhindo Syauswa4, Benjamin Kafudu4, Josue Subira4 and Nicolas d'Oreye3, (1)KIGAM Korea Institute of Geoscience and Mineral Resources, Daejeon, South Korea, (2)Virginia Polytechnic Institute and State University, Blacksburg, VA, United States, (3)European Center for Geodynamics and Seismology, Walferdange, Luxembourg, (4)Goma Volcano Observatory, Goma, Congo
Abstract:
The Virunga Volcanic Province of the Democratic Republic of Congo is at very high natural risk due to active volcanism. A Global Navigation Satellite System network, KivuGNet (Kivu Geodetic Network), has operated since 2009 for monitoring and research of the deformation of Nyamulagira and Nyiragongo volcanoes as well as tectonic deformation in the region. We detected an inflationary signal from the position time series observed in the network using our detection method, which is a combination of Kalman filtering and principal component analysis. The inflation occurred in October 2010 and lasted for about 6 months prior to the 2011 eruption at Nyamulagira volcano. The pre-eruptive inflationary signal is much weaker than the co-eruptive signal, but our method successfully detected the signal. The maximum horizontal and vertical displacements observed are ~14 mm and ~10 mm, respectively. A Mogi point source at a depth > 10 km can explain the displacement field suggesting a relatively deep source for the magma chamber. Continuous monitoring of the volcanic activity is essential for understanding the eruption cycle and assessing potential volcanic hazards.
