Positive and negative ionospheric disturbances prior to the 2016 christmas earthquake in Chile

Sotomayor-Beltran, Carlos

doi:10.1080/19475705.2018.1536081

Cited by 5 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Ref. [50], positive and negative VTEC anomalies were found before the December 2016 earthquake in Chile. Disturbances occurred 8 to 6 days before the earthquake within the Dobrovosky preparation region.…”

Section: Electron Density and Tec Anomaliesmentioning

confidence: 98%

Potential Earthquake Proxies from Remote Sensing Data

Boudriki Semlali,

Molina,

Carvajal Librado

et al. 2024

Sustainable Development

View full text Add to dashboard Cite

At present, there is no clear scientific evidence of reliable earthquake precursors that can be used as an early warning system. However, many studies have also reported the existence of faint signatures that appear to be coupled to the occurrence of earthquakes. These anomalies have traditionally been detected using data from in-situ sensors near high-seismicity regions. On the other hand, remote sensors offer the potential of large spatial coverage and frequent revisit time, allowing the observation of remote areas such as deserts, mountains, polar caps, or the ocean. This chapter revises the state-of-the-art of the understanding of lithosphere–atmosphere–ionosphere coupling. It also presents recent studies by the authors’ ongoing investigation on short-to-midterm earthquake precursors. The Earth observation variables discussed are (1) surface temperature anomalies from thermal infrared or microwave radiometer measurements, (2) atmospheric signatures, (3) ionospheric total electron density fluctuations or scintillation measured from GNSS signals, and (4) other geophysical variables, including geomagnetic field fluctuations, changes in the Schumann resonance frequency, or low-frequency electromagnetic radiation. However, despite the seismic hazard risk models that exist and the results shown by these studies, it is still very difficult to predict the occurrence of earthquakes.

show abstract

Section: Electron Density and Tec Anomaliesmentioning

confidence: 98%

Potential Earthquake Proxies from Remote Sensing Data

Boudriki Semlali,

Molina,

Carvajal Librado

et al. 2024

Sustainable Development

View full text Add to dashboard Cite

show abstract

“…Most previous studies on this topic use the TEC anomalous variations as earthquake precursors [21][22][23]. Only a small fraction of the studies on ionospheric perturbations related to earthquakes use ionospheric scintillation to do their correlation [24].…”

Section: Introductionmentioning

confidence: 99%

A Preliminary Study on Ionospheric Scintillation Anomalies Detected Using GNSS-R Data from NASA CYGNSS Mission as Possible Earthquake Precursors

et al. 2022

View full text Add to dashboard Cite

Ionospheric perturbations affect the propagation of electromagnetic waves. These perturbations, besides being a problem for space communications, satellite navigation, and Earth observation techniques, could also be used as another Earth observation tool. Several recent studies showed correlations with earthquakes with ionospheric anomalies, but almost all of them use ground stations to measure the Total Electron Content (TEC) variations, and, in particular, the ones occurring after an earthquake. Here, a preliminary study is presented on how the ionospheric scintillation measured with GNSS-R instruments over oceanic regions shows a small, but detectable correlation with the occurrence of earthquakes, which in some cases occurs before the earthquakes. This study uses GNSS-R data from NASA CYGNSS Mission to measure the ionospheric amplitude scintillation (S4) for 6 months from March 2019 to August 2019, applying a statistical analysis based on confusion matrixes, and the Receiver Operating Characteristic (ROC) curves to correlate S4 anomalous variations to earthquakes. A small positive correlation is found between the ionospheric scintillation and the earthquakes during the six previous days. However, the study has some weakness because (a) a small number (∼45) of large (M > 6) earthquakes over oceanic regions are studied, (b) the region studied is close to the geomagnetic equator, where ionospheric scintillations are usual, and (c) the overall correlation is small.

show abstract

“…These large events have puzzled scientists with pre-seismic signs, which are supposed to forecast the events before they happen. Although some scholars have found electromagnetic signs created from rocks [6][7][8], claiming that they will be detected at the ionosphere [9][10][11], it is still not clear about the propagation mechanism between the Earth's ground and the ionosphere [12,13].…”

Section: Introductionmentioning

confidence: 99%

South Atlantic Anomaly, Ionospheric Signals from Seismic Events

Hagen¹,

Azevedo²

2020

View full text Add to dashboard Cite

The purpose of this paper is to analyze the most significant events that occurred in the period 1996-2018 located under the South Atlantic Anomaly (SAA), where the earth's magnetic field is weaker and the trapped particles during the geomagnetic storms suffer decay over time. The time examined corresponds to the Solar Cycles 23 and 24; the area covered is defined by the following coordinates: 0N, −50S, 40E, −90W. Some significant events in this region reported Very Low Frequency (VLF) and Ultra Low Frequency (ULF) waves before the event, varying from minutes, hours, and even weeks before the earthquakes. Our study searches for a mechanism to explain why the crust creates electromagnetic signs detected at the ionosphere. Piezoelectric currents flow on the crust, combining with the magnetic field lines, temporarily producing pre-seismic electromagnetic pulses that are detected at the ionosphere prior to the events. The mechanism that allows electromagnetic signs to be detected at the ionosphere is also elucidated. These signs are brief, and they will cease with the beginning of the shock or shortly thereafter. However, some features contribute to making the signs impossible to detect, involving crust materials, location, magnitude, and depths. We suggest that these ionospheric events could happen for other kinds of hazard events, such as Volcanos.

show abstract

Positive and negative ionospheric disturbances prior to the 2016 christmas earthquake in Chile

Cited by 5 publications

References 34 publications

Potential Earthquake Proxies from Remote Sensing Data

Potential Earthquake Proxies from Remote Sensing Data

A Preliminary Study on Ionospheric Scintillation Anomalies Detected Using GNSS-R Data from NASA CYGNSS Mission as Possible Earthquake Precursors

South Atlantic Anomaly, Ionospheric Signals from Seismic Events

Contact Info

Product

Resources

About