scholarly journals Determining spatio-temporal characteristics of coseismic travelling ionospheric disturbances (CTID) in near real-time

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Boris Maletckii ◽  
Elvira Astafyeva
Keyword(s):  
Real Time ◽  
Tohoku Earthquake ◽  
Propagation Speed ◽  
High Rate ◽  
Ionospheric Disturbances ◽  
Temporal Characteristics ◽  
Travelling Ionospheric Disturbances ◽  
Spatio Temporal ◽  
Gnss Data ◽  
First Time

AbstractEarthquakes are known to generate ionospheric disturbances that are commonly referred to as co-seismic travelling ionospheric disturbances (CTID). In this work, for the first time, we present a novel method that enables to automatically detect CTID in ionospheric GNSS-data, and to determine their spatio-temporal characteristics (velocity and azimuth of propagation) in near-real time (NRT), i.e., less than 15 min after an earthquake. The obtained instantaneous velocities allow us to understand the evolution of CTID and to estimate the location of the CTID source in NRT. Furthermore, also for the first time, we developed a concept of real-time travel-time diagrams that aid to verify the correlation with the source and to estimate additionally the propagation speed of the observed CTID. We apply our methods to the Mw7.4 Sanriku earthquake of 09/03/2011 and the Mw9.0 Tohoku earthquake of 11/03/2011, and we make a NRT analysis of the dynamics of CTID driven by these seismic events. We show that the best results are achieved with high-rate 1 Hz data. While the first tests are made on CTID, our method is also applicable for detection and determining of spatio-temporal characteristics of other travelling ionospheric disturbances that often occur in the ionosphere driven by many geophysical phenomena.

scholarly journals An overview of methodologies for real-time detection, characterisation and tracking of traveling ionospheric disturbances developed in the TechTIDE project

2020 ◽  
Vol 10 ◽  
pp. 42
Author(s):  
Anna Belehaki ◽  
Ioanna Tsagouri ◽  
David Altadill ◽  
Estefania Blanch ◽  
Claudia Borries ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Tracking System ◽  
Warning System ◽  
Satellite System ◽  
Ionospheric Disturbances ◽  
Time Activity ◽  
Travelling Ionospheric Disturbances ◽  
Additional Information ◽  
Global Navigation Satellite

The main objective of the TechTIDE project (warning and mitigation technologies for travelling ionospheric disturbances effects) is the development of an identification and tracking system for travelling ionospheric disturbances (TIDs) which will issue warnings of electron density perturbations over large world regions. The TechTIDE project has put in operation a real-time warning system that provides the results of complementary TID detection methodologies and many potential drivers to help users assess the risks and develop mitigation techniques tailored to their applications. The TechTIDE methodologies are able to detect in real time activity caused by both large-scale and medium-scale TIDs and characterize background conditions and external drivers, as an additional information required by the users to assess the criticality of the ongoing disturbances in real time. TechTIDE methodologies are based on the exploitation of data collected in real time from Digisondes, Global Navigation Satellite System (GNSS) receivers and Continuous Doppler Sounding System (CDSS) networks. The results are obtained and provided to users in real time. The paper presents the achievements of the project and discusses the challenges faced in the development of the final TechTIDE warning system.

scholarly journals First GPS TEC maps of ionospheric disturbances induced by reflected tsunami waves: The Tohoku case study

2016 ◽  
Author(s):  
L. Tang ◽  
Y. Zhao ◽  
J. An
Keyword(s):  
Gravity Waves ◽  
Arrival Time ◽  
Tohoku Earthquake ◽  
Internal Gravity Waves ◽  
Ionospheric Disturbances ◽  
Propagation Characteristics ◽  
Tsunami Waves ◽  
Travelling Ionospheric Disturbances ◽  
Ionospheric Height

Abstract. The straight tsunami waves from epicenter can be reflected when they reach to coasts or underwater obstacles. In this study, we present the first ionospheric maps of reflected tsunami signature caused by the great 11 March 2011 Tohoku earthquake using the dense GPS network GEONET in Japan. We observed tsunami-like travelling ionospheric disturbances (TIDs) with similar propagation characteristics in terms of waveform, horizontal velocity, direction, period and arrival time compared to the reflected tsunami at the sea-level, indicating the TIDs are induced by the reflected tsunami. The results confirm the atmospheric internal gravity waves (IGWs) produced by reflected tsunami can also propagate upward to the atmosphere and interact with the plasma at the ionospheric height.

scholarly journals Report on a characteristic oscillation about 38 mHz (26 s) in northeastern Japan following surface wave of the 2011 Tohoku megathrust earthquake

2015 ◽  
Vol 202 (1) ◽  
pp. 419-423 ◽  
Author(s):  
Yuta Mitsui ◽  
Kosuke Heki
Keyword(s):  
Surface Wave ◽  
Velocity Structure ◽  
Tohoku Earthquake ◽  
Spectral Ratio ◽  
2011 Tohoku Earthquake ◽  
High Rate ◽  
The 2011 Tohoku Earthquake ◽  
Northeastern Japan ◽  
Characteristic Oscillation ◽  
Gnss Data

Abstract We try to detect an unidentified signal from the surface motion at northeastern Japan immediately after the 2011 Tohoku earthquake. A focused frequency range is 10–100 mHz (10–100 s). We find a peaky signal with frequency of about 38 mHz (26 s) based on the horizontal-to-vertical (H/V) spectral ratio using the high-rate GNSS data at 382 GEONET stations. We are not able to identify locality of the signal. The signal appears several minutes after the passing of surface wave fronts. The duration of the signal is about 2 min. Since the origin of the 38 mHz signal is unlikely to be local hydrologic tremors, tectonic tremors, or the tsunami, we speculate that the 38 mHz signal originates from a kind of a characteristic oscillation of Northeastern Japan triggered by the 2011 Tohoku earthquake. A normal-mode simulation implies that high-order radial overtones could create the signal with a spherically-layered velocity structure, however, the detailed mechanism of the signal still remains a mystery.

Application of high-rate GPS for earthquake rapid response and modelling: a case in the 2019 Mw 7.1 Ridgecrest earthquake

2020 ◽  
Vol 222 (3) ◽  
pp. 1923-1935
Author(s):  
Jin Fang ◽  
Caijun Xu ◽  
Jianfei Zang ◽  
Yangmao Wen ◽  
Chuang Song ◽  
...  
Keyword(s):  
Real Time ◽  
Moment Tensor ◽  
Propagation Speed ◽  
Source Model ◽  
High Rate ◽  
Centroid Moment Tensor ◽  
Magnitude Scaling ◽  
Global Positioning ◽  
Slip Event ◽  
Kaikoura Earthquake

SUMMARY The 2019 Mw 7.1 Ridgecrest earthquake opens an opportunity to investigate how soon we can produce a reliable fault geometry and subsequently a robust source model based on high-rate Global Positioning System (GPS) data. In this study, we conduct peak ground displacement (PGD) magnitude scaling, real-time centroid moment tensor (CMT) calculation and rapid kinematic slip inversion. We conclude that a four-station PGD warning with a magnitude of Mw 7.03 can be issued at 24 s after initiation of the rupture. Fast CMT inversion can initially recover the correct nodal planes at 30 s. The kinematic slip model reveals that the Mw 7.1 earthquake is a predominant dextral strike-slip event with both normal and thrust components resolved. The earthquake shows a bilateral rupture with a low propagation speed of ∼2.1 km s−1 and a slip maxima of ∼4 m. The total moment is 5.18 × 1019 N m (Mw 7.11). We further suggest that a reasonable source model will be available in a simulated real-time mode within 30 s after the earthquake occurring, without using full high-rate GPS waveforms. This research highlights the significance of high-rate GPS for rapid earthquake response and modelling of kinematic rupture, which is also generalized by the hypothetical real-time GPS analysis for the 2016 Mw 7.8 Kaikoura earthquake and the 2010 Mw 7.2 El Mayor-Cucapah earthquake.

RTView 1.0: a new software for High Rate GNSS data analysis and visualization in Real Time

2020 ◽  
Author(s):  
Francesco Pandolfo ◽  
Mario Mattia ◽  
Massimo Rossi ◽  
Valentina Bruno
Keyword(s):  
Open Source ◽  
Real Time ◽  
Web Application ◽  
Software Tool ◽  
High Rate ◽  
Display Time ◽  
North East ◽  
The North ◽  
Displacement Vectors ◽  
Gnss Data

<p>Volcano ground deformations needs hardware and software tools of high complexity related to the processing of raw GNSS data, filtering of outliers and spikes and clear visualization of displacements occurring in real time. In this project we developed a web application for high rate real time signals visualization from permanent GNSS  remote stations managed by INGV OE (Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo). Currently the new software tool is able to import GNSS data processed by some of the most important high rate real time software like GeoRTD® (owned by Geodetics), GNSS Spider® (Owned by Leica Geosystems) and RTKlib. The tool is based on the Grafana open source platform and InfluxDB open source database. Various dashboards have been configured to display time series of the North-East-Up coordinates to monitor single stations, to compare signals coming from different data sources and to display the displacement vectors on the map. We also applied a simple alghoritm for the detection of abnormal variations due to impending volcanic activity.This web interface is applied to different active Italian volcanoes as Etna (Sicily), Stromboli (Aeolian Islands) and Phlegrean Fields (Naples). We tested the performance of this software using as a case study the 24th December 2018 dike intrusion on the Etna volcano.</p>

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