Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements

Long-duration events have been recorded at several active, andesitic volcanoes. Their main characteristics are a single, sharp frequency peak, and an exceptionally long coda. Because their seismograms resemble a screw, these signals are called "tornillos" in Colombia. These events have bee...

Full description

Bibliographic Details
Main Authors: M. Hellweg, D. Seidl, R. A. Torres C., D. M. Gómez M., H. Rademacher
Format: Article
Language:English
Published: Istituto Nazionale di Geofisica e Vulcanologia (INGV) 1999-06-01
Series:Annals of Geophysics
Subjects:
Online Access:http://www.annalsofgeophysics.eu/index.php/annals/article/view/3726
_version_ 1818479783223230464
author M. Hellweg
D. Seidl
R. A. Torres C.
D. M. Gómez M.
H. Rademacher
author_facet M. Hellweg
D. Seidl
R. A. Torres C.
D. M. Gómez M.
H. Rademacher
author_sort M. Hellweg
collection DOAJ
description Long-duration events have been recorded at several active, andesitic volcanoes. Their main characteristics are a single, sharp frequency peak, and an exceptionally long coda. Because their seismograms resemble a screw, these signals are called "tornillos" in Colombia. These events have been recorded during different stages of volcanic activity at various volcanoes worldwide. Tornillos have occurred for example, as a short-term precursor to eruptions at Galeras volcano, Colombia (1992-1993); and at Asama volcano, Japan, (1983). At Tokachi volcano, Japan, they were recorded after an eruption (1989). The Tornillo's dominant frequency appears to be related to the time of occurrence during an eruption cycle. It is independent of epicentral distance, azimuth, travel time, and lapse time, indicating that it is a source characteristic. Damping coefficients for the tornillo's coda range between 0.002 and 0.02. In contrast, damping coefficients for normal long-period events lies between 0.010 and 0.025 and for volcano-tectonic events between 0.010 and 0.040. In March 1996, the Galeras seismic network, which consists of short period, single-component seismometers, was augmented with a broadband, three-component station. This station, installed 1.5 km south of Galeras active cone, recorded a series of six tornillos. Narrowband and broadband tornillo records have similar characteristics in the time and frequency domains.
first_indexed 2024-12-10T11:15:18Z
format Article
id doaj.art-7d336847b35b45878e1c6294b805dd04
institution Directory Open Access Journal
issn 1593-5213
2037-416X
language English
last_indexed 2024-12-10T11:15:18Z
publishDate 1999-06-01
publisher Istituto Nazionale di Geofisica e Vulcanologia (INGV)
record_format Article
series Annals of Geophysics
spelling doaj.art-7d336847b35b45878e1c6294b805dd042022-12-22T01:51:12ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X1999-06-0142310.4401/ag-3726Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurementsM. HellwegD. SeidlR. A. Torres C.D. M. Gómez M.H. RademacherLong-duration events have been recorded at several active, andesitic volcanoes. Their main characteristics are a single, sharp frequency peak, and an exceptionally long coda. Because their seismograms resemble a screw, these signals are called "tornillos" in Colombia. These events have been recorded during different stages of volcanic activity at various volcanoes worldwide. Tornillos have occurred for example, as a short-term precursor to eruptions at Galeras volcano, Colombia (1992-1993); and at Asama volcano, Japan, (1983). At Tokachi volcano, Japan, they were recorded after an eruption (1989). The Tornillo's dominant frequency appears to be related to the time of occurrence during an eruption cycle. It is independent of epicentral distance, azimuth, travel time, and lapse time, indicating that it is a source characteristic. Damping coefficients for the tornillo's coda range between 0.002 and 0.02. In contrast, damping coefficients for normal long-period events lies between 0.010 and 0.025 and for volcano-tectonic events between 0.010 and 0.040. In March 1996, the Galeras seismic network, which consists of short period, single-component seismometers, was augmented with a broadband, three-component station. This station, installed 1.5 km south of Galeras active cone, recorded a series of six tornillos. Narrowband and broadband tornillo records have similar characteristics in the time and frequency domains.http://www.annalsofgeophysics.eu/index.php/annals/article/view/3726volcanoesseismic eventsbroadband recordtornillosGaleras volcano
spellingShingle M. Hellweg
D. Seidl
R. A. Torres C.
D. M. Gómez M.
H. Rademacher
Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
Annals of Geophysics
volcanoes
seismic events
broadband record
tornillos
Galeras volcano
title Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
title_full Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
title_fullStr Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
title_full_unstemmed Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
title_short Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements
title_sort tornillo seismic events at galeras volcano colombia a summary and new information from broadband three component measurements
topic volcanoes
seismic events
broadband record
tornillos
Galeras volcano
url http://www.annalsofgeophysics.eu/index.php/annals/article/view/3726
work_keys_str_mv AT mhellweg tornilloseismiceventsatgalerasvolcanocolombiaasummaryandnewinformationfrombroadbandthreecomponentmeasurements
AT dseidl tornilloseismiceventsatgalerasvolcanocolombiaasummaryandnewinformationfrombroadbandthreecomponentmeasurements
AT ratorresc tornilloseismiceventsatgalerasvolcanocolombiaasummaryandnewinformationfrombroadbandthreecomponentmeasurements
AT dmgomezm tornilloseismiceventsatgalerasvolcanocolombiaasummaryandnewinformationfrombroadbandthreecomponentmeasurements
AT hrademacher tornilloseismiceventsatgalerasvolcanocolombiaasummaryandnewinformationfrombroadbandthreecomponentmeasurements