Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis
The properties of a worldwide data set of 91 radon (^(222)Rn) anomalies (the frequency of occurrence, the precursor time interval, and the distribution of peak amplitudes) are correlated with earthquake data such as the respective magnitude and epicentral distance. These anomalies were reported as p...
Published in: | Journal of Geophysical Research: Solid Earth |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Geophysical Union
1981
|
Subjects: | |
Online Access: | https://doi.org/10.1029/JB086iB10p09397 |
id |
ftcaltechauth:oai:authors.library.caltech.edu:nmxt7-wsz14 |
---|---|
record_format |
openpolar |
spelling |
ftcaltechauth:oai:authors.library.caltech.edu:nmxt7-wsz14 2024-10-13T14:08:33+00:00 Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis Hauksson, Egill 1981-10 https://doi.org/10.1029/JB086iB10p09397 unknown American Geophysical Union https://doi.org/10.1029/JB086iB10p09397 eprintid:38331 info:eu-repo/semantics/openAccess Other Journal of Geophysical Research B, 86(B10), 9397-9410, (1981-10) info:eu-repo/semantics/article 1981 ftcaltechauth https://doi.org/10.1029/JB086iB10p09397 2024-09-25T18:46:46Z The properties of a worldwide data set of 91 radon (^(222)Rn) anomalies (the frequency of occurrence, the precursor time interval, and the distribution of peak amplitudes) are correlated with earthquake data such as the respective magnitude and epicentral distance. These anomalies were reported as precursors to earthquakes in the United States, USSR, China, Japan, and Iceland. Although the data set is incomplete and limited by experimental deficiencies, several consistent patterns emerge. Radon anomalies from different tectonic regions show similar patterns. The radon anomalies occur at greater epicentral distances for earthquakes of the larger magnitude. Anomalies preceding large earthquakes (M ≥ 6) are frequently observed at a distance of 100 to 500 km. These distances are larger than several times the rupture dimensions of the future earthquakes. The time from the onset of an anomaly to the time of the earthquake (the precursor time) increases with magnitude but decreases with distance between epicenter and radon station. In addition, radon anomalies are observed more frequently prior to large earthquakes than prior to small ones, indicating that the preparation zone increases in size as magnitude increases. The peak amplitude does not scale with magnitude but forms a consistent pattern with epicentral distance in that the larger the earthquake magnitude, the farther away the largest amplitudes tend to occur. The preparation zone of the earthquake where the anomalies occur forms an almost continuous annulus that expands with time away from the future rupture zone. The outer radius of this annulus scales with the earthquake magnitude. Model calculations indicate that strain fields of at most 10^(−6) to 10^(−8) strain caused the radon anomalies. If these strains are divided by the appropriate precursor time, minimum strain rates from 10^(−7) day^(−1) to 10^(−10) day^(−1) are obtained. Such small strains and strain rates suggest that in most cases neither mechanical crack growth induced by ... Article in Journal/Newspaper Iceland Caltech Authors (California Institute of Technology) Journal of Geophysical Research: Solid Earth 86 B10 9397 9410 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
description |
The properties of a worldwide data set of 91 radon (^(222)Rn) anomalies (the frequency of occurrence, the precursor time interval, and the distribution of peak amplitudes) are correlated with earthquake data such as the respective magnitude and epicentral distance. These anomalies were reported as precursors to earthquakes in the United States, USSR, China, Japan, and Iceland. Although the data set is incomplete and limited by experimental deficiencies, several consistent patterns emerge. Radon anomalies from different tectonic regions show similar patterns. The radon anomalies occur at greater epicentral distances for earthquakes of the larger magnitude. Anomalies preceding large earthquakes (M ≥ 6) are frequently observed at a distance of 100 to 500 km. These distances are larger than several times the rupture dimensions of the future earthquakes. The time from the onset of an anomaly to the time of the earthquake (the precursor time) increases with magnitude but decreases with distance between epicenter and radon station. In addition, radon anomalies are observed more frequently prior to large earthquakes than prior to small ones, indicating that the preparation zone increases in size as magnitude increases. The peak amplitude does not scale with magnitude but forms a consistent pattern with epicentral distance in that the larger the earthquake magnitude, the farther away the largest amplitudes tend to occur. The preparation zone of the earthquake where the anomalies occur forms an almost continuous annulus that expands with time away from the future rupture zone. The outer radius of this annulus scales with the earthquake magnitude. Model calculations indicate that strain fields of at most 10^(−6) to 10^(−8) strain caused the radon anomalies. If these strains are divided by the appropriate precursor time, minimum strain rates from 10^(−7) day^(−1) to 10^(−10) day^(−1) are obtained. Such small strains and strain rates suggest that in most cases neither mechanical crack growth induced by ... |
format |
Article in Journal/Newspaper |
author |
Hauksson, Egill |
spellingShingle |
Hauksson, Egill Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
author_facet |
Hauksson, Egill |
author_sort |
Hauksson, Egill |
title |
Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
title_short |
Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
title_full |
Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
title_fullStr |
Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
title_full_unstemmed |
Radon content of groundwater as an earthquake precursor: Evaluation of worldwide data and physical basis |
title_sort |
radon content of groundwater as an earthquake precursor: evaluation of worldwide data and physical basis |
publisher |
American Geophysical Union |
publishDate |
1981 |
url |
https://doi.org/10.1029/JB086iB10p09397 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Journal of Geophysical Research B, 86(B10), 9397-9410, (1981-10) |
op_relation |
https://doi.org/10.1029/JB086iB10p09397 eprintid:38331 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1029/JB086iB10p09397 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
86 |
container_issue |
B10 |
container_start_page |
9397 |
op_container_end_page |
9410 |
_version_ |
1812815222612688896 |