Linking SO2 emission rates and seismicity by continuous wavelet transform: implications for volcanic surveillance at San Cristbal volcano, Nicaragua
Artikel i vetenskaplig tidskrift, 2016

San Cristbal volcano is the highest and one of the most active volcanoes in Nicaragua. Its persistently high activity during the past decade is characterized by strong degassing and almost annual VEI 1-2 explosions, which present a threat to the local communities. Following an eruption on 8 September 2012, the intervals between eruptions decreased significantly, which we interpret as the start of a new eruptive phase. We present here the results of semi-continuous SO2 flux measurements covering a period of 18 months, obtained by two scanning UV-DOAS instruments installed as a part of the network for observation of volcanic and atmospheric change project, and the results of real-time seismic amplitude measurements (RSAM) data. Our data comprise a series of small to moderately explosive events in December 2012, June 2013 and February 2014, which were accompanied by increased gas emissions and seismicity. In order to approach an early warning strategy, we present a statistical method for the joint analysis of gas flux and seismic data, by using continuous wavelet transform and cross-wavelet transform (XWT) methods. This analysis shows that the XWT coefficients of SO2 flux and RSAM are in good agreement with the occurrence of eruptive events and thus may be used to indicate magma ascent into the volcano edifice. Such multi-parameter surveillance efforts can be useful for the interpretation and surveillance of possible eruptive events and could thus be used by local institutions for the prediction of upcoming volcanic unrest.

analysis

Volcanic SO2

DOAS

variability

flux measurements

eruption

time-frequency localization

RSAM

oscillations

Geology

CWT and XWT

signal

system

assimilation

kalman filter

Wavelets

gas emissions

Författare

Alexander Vladimir Conde Jacobo

Chalmers, Rymd- och geovetenskap, Optisk fjärranalys

S. Bredemeyer

GEOMAR - Helmholtz Zentrum für Ozeanforschung Kiel

J. A. Saballos

Instituto Nicaragüense de Estudios Territoriales

Bo Galle

Chalmers, Rymd- och geovetenskap, Optisk fjärranalys

T. H. Hansteen

GEOMAR - Helmholtz Zentrum für Ozeanforschung Kiel

International Journal of Earth Sciences

1437-3254 (ISSN) 1437-3262 (eISSN)

Vol. 105 1453-1465

Ämneskategorier

Annan geovetenskap och miljövetenskap

DOI

10.1007/s00531-015-1264-1