@misc{10481/72574,
year = {2022},
month = {1},
url = {http://hdl.handle.net/10481/72574},
abstract = {Understanding seismic tremor wavefields can shed light on the complex functioning of a volcanic system and,
thus, improve volcano monitoring systems. Usually, several seismic stations are required to detect, characterize, and
locate volcanic tremors, which can be difficult in remote areas or low-income countries. In these cases, alternative
techniques have to be used. Here, we apply a data-reduction approach based on the analysis of three-component
seismic data from two co-located stations operating in different times to detect and analyze long-duration tremors.
We characterize the spectral content and the polarization of 355 long-duration tremors recorded by a seismic sensor
located 9.5 km SE from the active vent of Copahue volcano in the period 2012–2016 and 2018–2019. We classified
them as narrow- (NB) and broad-band (BB) tremors according to their spectral content. Several parameters describe
the characteristic peaks composing each NB episode: polarization degree, rectilinearity, horizontal azimuth, vertical
incidence. Moreover, we propose two coefficients CP and CL for describing to what extent the wavefield is polarized.
For BB episodes, we extend these attributes and express them as a function of frequency. We compare the occurrence
of NB and BB episodes with the volcanic activity (including the level of the crater lake, deformation, temperature, and
explosive activity) to get insights into their mechanisms. This comparison suggests that the wavefield of NB tremors
becomes more linearly polarized during eruptive episodes, but does not provide any specific relationship between
the tremor frequency and volcanic activity. On the other hand, BB tremors show a seasonal behavior that would be
related to the activity of the shallow hydrothermal system.},
organization = {Spanish Government	CTM2016.77315},
organization = {National University of Rio Negro	PI40-A-548},
publisher = {Springer},
keywords = {Tremor characterization},
keywords = {Data reduction methods},
keywords = {Non-eruptive tremor},
keywords = {Copahue volcano},
title = {Long‑duration seismicity and their relation to Copahue volcano unrest},
doi = {10.1186/s40623-021-01561-7},
author = {Melchor, Iván and Almendros González, Francisco Javier},
}