NH4.1 | Short-term Earthquakes Forecast (StEF) and multi-parametric time-Dependent Assessment of Seismic Hazard (t-DASH)
EDI
Short-term Earthquakes Forecast (StEF) and multi-parametric time-Dependent Assessment of Seismic Hazard (t-DASH)
Co-organized by EMRP1/ESSI4/GI5, co-sponsored by JpGU and EMSEV
Convener: Valerio Tramutoli | Co-conveners: Pier Francesco Biagi, Carolina Filizzola, Nicola Genzano, Rachel Grant
Orals
| Fri, 19 Apr, 10:45–12:30 (CEST)
 
Room 1.31/32
Posters on site
| Attendance Fri, 19 Apr, 16:15–18:00 (CEST) | Display Fri, 19 Apr, 14:00–18:00
 
Hall X4
Posters virtual
| Attendance Fri, 19 Apr, 14:00–15:45 (CEST) | Display Fri, 19 Apr, 08:30–18:00
 
vHall X4
Orals |
Fri, 10:45
Fri, 16:15
Fri, 14:00
From the real-time integration of multi-parametric observations is expected the major contribution to the development of operational t-DASH systems suitable for supporting decision makers with continuously updated seismic hazard scenarios. A very preliminary step in this direction is the identification of those parameters (seismological, chemical, physical, biological, etc.) whose space-time dynamics and/or anomalous variability can be, to some extent, associated with the complex process of preparation of major earthquakes.
This session wants then to encourage studies devoted to demonstrate the added value of the introduction of specific, observations and/or data analysis methods within the t-DASH and StEF perspectives. Therefore, studies based on long-term data analyses, including different conditions of seismic activity, are particularly encouraged. Similarly welcome will be the presentation of infrastructures devoted to maintain and further develop our present observational capabilities of earthquake related phenomena also contributing in this way to build a global multi-parametric Earthquakes Observing System (EQuOS) to complement the existing GEOSS initiative.
To this aim this session is not addressed just to seismology and natural hazards scientists but also to geologist, atmospheric sciences and electromagnetism researchers, whose collaboration is particular important for fully understand mechanisms of earthquake preparation and their possible relation with other measurable quantities. For this reason, all contributions devoted to the description of genetic models of earthquake’s precursory phenomena are equally welcome.

Orals: Fri, 19 Apr | Room 1.31/32

Chairpersons: Valerio Tramutoli, Nicola Genzano, Dimitar Ouzounov
10:45–10:50
10:50–11:00
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EGU24-20006
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On-site presentation
Lixin Wu, Busheng Xie, Dingyi Wu, Xiao Wang, Ziqing Wang, Yifang Ding, Youyou Xu, and Wenfei Mao

Multiple parameters anomalies appeared before medium-strong earthquakes have long been observed and analyzed. The spatio-temporal relations of multiple anomalies were attributed to the coupling of lithosphere, coversphere, atmosphere and ionosphere (LCAI in brief) related with the seismogenious activity and final shocking. However, the mechanism of LCAI coupling is not yet clear and the process of LCAI coupling is much fuzzy, which hinders the scrutinizing of reported anomalies, and leads to great difficulty in discriminating the inconsistency for single parameter as well as the uncertainty among multiple parameters.

From laboratory experiments on rock specimens partly loaded to fracturing we discovered that there were pressure stimulated rock current (PSRC) developing with the applied pressure, and there was stepped increment of PSRC as well as sharp rise of PSRC appearing in the late phase of loading rock to failure. The measured PSRCs were measured in an amplitude of 2~8000na, which depending on rock-minerals and porewater of different rock specimen. The enhancement of surface infrared radiation and the reduction of surface rock dielectric, which lead subsequently to the enhancement of microwave brightness temperature (MBT), could be attributed the production of PSRC and its propagation to rock surface both in laboratory and seismogenious zone.

Ground observations in Luding, China, and Fukushima, Japan, showed that the arriving of PSRC from underground was able to disturb the near-surface electric field, and led further to the local atmospheric ionization and earthquake light near ground surface. Abnormal drop of atmospheric electric field and simultaneous rise of MBT were observed preceding the M6.8 Luding earthquake, 2022, and earthquake lighting and horizontal magnetic vector disturbance were observed accompanying with the M7.3 Fukushima earthquake, 2023.

The arrival of PSRC from seimogenious zone or hypocenter is to change the atmospheric electric field, which was believed being able to penetrate upward from ground surface to ionosphere. An atmospheric electric field penetration model was modified and used to simulated the ionospheric disturbance due to the seismic PSRC inhomogeneous appeared on ground surface. The ionospheric TEC disturbance related with the M8.0 Wenchuan earthquake in 2008, the M9.0 Tohoku earthquake in 2011, the M7.8 Nepal earthquake in 2015 and the M7.5 Turkey earthquake in 2022 were carefully simulated, respectively, according to the position of MBT anomalies or supposed PSRC occurrence. The simulation results were visualized in a 3D spheroid space and contrasted to the reported TEC anomalies retrieved from satellite or ground observations. Particularly for the great Nepal earthquake in 2015, we scrutinized the observed multiple anomalies, including TEC and VLF, possible related with the LCAI coupling, and rooted the seismic anomalies to the simulated underground high-stress accumulation regions on and above the subduction fault.

How to cite: Wu, L., Xie, B., Wu, D., Wang, X., Wang, Z., Ding, Y., Xu, Y., and Mao, W.: Seismic LCAI Coupling Supported by Pressure Stimulated Rock Current: Multi-parameter Observations and Numerical Simulation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20006, https://doi.org/10.5194/egusphere-egu24-20006, 2024.

11:00–11:10
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EGU24-12838
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On-site presentation
Elsa Leticia Flores-Marquez, Xochilt Esther Zambrana-Areas, and Alejandro Ramirez-Rojas

Nicaragua is located on the western margin of the Caribbean plate near its interaction with the Cocos plates. The Caribbean plate is surrounded by four major tectonic plates: Cocos at the southwest, Nazca at the south, the North American and South American to the north and southeast respectively. The Cocos plate subducts the Caribbean plate at rates of aproximately 70 to 90 mm/yr having a steeper dip around 75° and 80°. The Central American subduction zone is seismically active. The associated volcanic arc consists mainly of basaltic-andesitic quaternary volcanic rocks (predominantly pyroclastic and lava flows). The seismicity, although constant, has not exceeded earthquakes of Ms 7.3. We analyzed the period between 2000 and 2023 in terms of entropy in natural time domain. Our analysis in terms of Gutemberg-Richter law shows b-value fluctuation ranging between 0.53 and 1.03 by year. Regarding the analysis of entropy fluctuations, it indicates the correlations are short-range, so we consider that the seismic sequence behaves as a Markovian process.

How to cite: Flores-Marquez, E. L., Zambrana-Areas, X. E., and Ramirez-Rojas, A.: Nicaragua seismicity study in terms of entropy fluctuations in natural time domain, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12838, https://doi.org/10.5194/egusphere-egu24-12838, 2024.

11:10–11:20
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EGU24-7299
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ECS
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On-site presentation
Lorenzo Chemeri, Marco Taussi, Davide Fronzi, Jacopo Cabassi, Alberto Tazioli, Alberto Renzulli, and Orlando Vaselli

It is well established in geosciences that Mw > 4 earthquakes are expected to produce changes in the geochemistry of the waters circulating close to epicentral area. Therefore, such modifications are commonly considered as precursory signals and strictly related to the earthquake preparation processes and seismic cycles. Since most of these changes are transitory and site-sensitive, the identification of possible and suitable seismic precursors represents one of the major challenges for geoscientists. Consequently, the development of multi-parametric water monitoring networks located in earthquake-prone areas is a fundamental step toward a better understanding of the relationship between the seismic cycle and the occurrence of possible tracers.

The northern offshore area of the Marche Region was hit by 5.2 and 5.5 Mw earthquakes (Lat. 43.9830, Long. 13.4240, 5 km depth) on November 9, 2022 during which no fatalities or serious damages were recorded. In this work we report the preliminary results obtained from a pre- and post-seismic monitoring focused on waters collected from three piezometers (with a depth ranging from 15 to 30 m) located in the Mt. Conero Area (central-eastern Italy): Monte Acuto (MAC), Vallemiano (VAL), and Betelico (BET), situated ca. 40-50 km from the epicenter. All waters were sampled within 48 hours from the mainshock and periodically (on a monthly or quarterly basis) collected for one year after the event. The water chemistry of BET sample was available from May to October 2022, i.e., up to six months before the event. While the water samples MAC and VAL did not show any relevant chemical and isotopic variations, those collected from BET displayed strikingly significant modifications. The geochemical facies, characterized by a calcium-bicarbonate and a TDS (Total Dissolved Solids) < 1000 mg/L, typical of shallow aquifers, indeed became sodium-chlorine with TDS > 3500 mg/L, since the end of June 2022, i.e., about four months before the mainshock. About a week after the main events, the water chemistry returned to be Ca-HCO3. Boron, Li, Sr and Rb concentrations also showed significant increments starting from June whereas those of Fe, Mn, Ni, Cu, Zn and Pb displayed overwhelming increases (up to 50 times their pre-seismic values) in those samples collected in the days following the mainshocks. Consequently, particular emphasis was placed on addressing the origin of these changes and evaluating their possible relation with the seismic event. We can hypothesize that a mixing process between shallow aquifer and Na-Cl connate (or thermal) waters occurred, the latter being widely reported in the Adriatic foredeep deposits. The observed chemical variations might likely be related to changes in the relative pressure between superimposed and separated aquifers triggered by modifications in the stress rates associated with the seismic cycle. Moreover, variations in the hydraulic heads resulting in a temporary connection between two distinct aquifers would also explain the transitory changes detected at BET. If confirmed, these variations would be among the most strikingly impressive geochemical evidences ever detected before a seismic event or, at least, ever reported in the literature.

 

 

How to cite: Chemeri, L., Taussi, M., Fronzi, D., Cabassi, J., Tazioli, A., Renzulli, A., and Vaselli, O.: Groundwater geochemical anomalies in Mt. Conero area (central-eastern Italy) related to the pre- and post- 5.2 and 5.5 Mw Marche offshore seismic events (November 9, 2022), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7299, https://doi.org/10.5194/egusphere-egu24-7299, 2024.

11:20–11:30
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EGU24-13120
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solicited
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Highlight
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On-site presentation
Francesco Vespe, Jan Dousa, Carlo Doglioni, Eleonora Ficini, Olimpia Masci, Giovanni Nico, Jakub Nosek, Pavel Vaclavovic, Gianluca Sottili, Davide Zaccagnino, Luis Mendes, and Francisco Amarillo-Fernandez

This work presents some results achieved in the frame of TILDE project (Tidal Interplate Lithospheric Deformation of Earth). The main goal of TILDE project was the estimation of Local Solid Earth Tides (LSET); i.e. models which depends on the geographical position of the selected sites. The LSET models are built estimating Love and Shida numbers for each station and for each tidal constituents. The objectives were to investigate possible correlations between LSET and geological/geophysical events, such as tectonic plates movements, earthquakes and volcanic activities. GNSS data collected at 98 stations, split into global and regional networks have been used. The global network consists of 73 GNSS stations which have piled up a stack of data 20 years long. The regional networks consist of 25 stations, 7 located in New Zealand, 1 in Kamchatka, and 17 stations in Italy for which 3 year-long time series of data are available.

The LSET models have been achieved using GNSS coordinates expressed both in geocentric XYZ and local NEU references, estimated in Precise Post Processing mode, with a sampling rate in turn of 1 day and 3 hours.  Different GNSS solutions have been generated according the objectives of the project. The first one is the background solution in which the full IERS2010 tides model has been applied. The second solution is obtained by switching off the tides model. The third one is the solution in which only the Long-Periodic Tides (LPT) has been switched off. This last solution has been applied in order to lower the level of flickering of GNSS time series when Love and Shida numbers of LPT had to be estimated.

This analysis showed that there is a correlation between the latitude measured from the tectonic equator and Love numbers. This confirms the theory that moon tides contribute to trigger tectonic movements.

An interesting result, relevant for the assessment and potential precursiveness of the risk of seismic hazards, was the correlation found between the variation in time of Love numbers of diurnal (K1) and semi-diurnal (M2) tides and the occurrence of earthquakes nearby GNSS sites.  At this purpose we selected GNSS global stations which were at a distance <200 Km from the epicentre of EQ events. The investigation has outlined that almost the seismic events are got ahead by a downfall of Love numbers. It seems that each earthquake event cannot be characterized only by the type of slip occurred along faults: compressive (i.e., reverse fault), extensional (i.e., normal fault), strike slip or combination of them. This result could be explained with the rigidity of the crust/mantle which play a major role in triggering seismic events. For smaller values of Love number we have indeed a more rigid response of Earth to Tidal forcing.

How to cite: Vespe, F., Dousa, J., Doglioni, C., Ficini, E., Masci, O., Nico, G., Nosek, J., Vaclavovic, P., Sottili, G., Zaccagnino, D., Mendes, L., and Amarillo-Fernandez, F.: Local Solid Earth Tides and Their potential use in assessing and forecasting the risk of seismic hazards, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13120, https://doi.org/10.5194/egusphere-egu24-13120, 2024.

11:30–11:40
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EGU24-3264
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Highlight
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On-site presentation
Xuhui Shen, xuemin zhang, zhima Zeren, Shufan Zhao, Qinqin Liu, Roberto Battiston, Angelo De Santis, Tiger Liu, Valerio Tramutoli, Livio Conti, and Rui Yan
As the first geophysical field observation satellite mission in China, CSES-01 has been operating in orbit for six years and, based on its optimal performance, it will prolong its life after CSES-02's launch in orbit in order to partly overlap the two missions. In retrospect, CSES-01 acquired an amount of data such as geomagnetic field, low-frequency electromagnetic waves, in-situ plasma content, and temperature, charged particles as well ionospheric plasma, while more than 70 M7+  and 700 M6+  earthquakes  have been recorded in the globe, together with a series of space weather and volcano phenomena. 
The large amount of data collected has provided new ground for in depth exploration on statistical analysis of earthquake precursors as well as providing clear evidence for the feasibility of space-based co-seismic observation, helping the development of quantitative modeling of the Lithosphere-Atmosphere-Ionosphere Coupling mechanism focusing on its atmospheric and electromagnetic wave channel.
The following prospect plan, CSES-02, is under development by China-Italy joint team and is due to launch in 2024, which means that we will have two CSES satellites simultaneously in orbit from 2024. Such an increase in observational capabilities will strongly support the implementation of multi-parametric observation systems, both from the ground and from satellites, capable of significantly improving precision and reliability of earthquake forecasts. In addition, the new International Meridian Circle Project  (IMCP)   will be implemented as a ground-based observation network with its primary objectives of monitoring the geomagnetical field, space weather, and interaction among Lithosphere-Atmosphere-Ionosphere. The main tasks of IMCP are global data sharing, joint research on space weather and natural hazards, global change, and many other science fields. 

How to cite: Shen, X., zhang, X., Zeren, Z., Zhao, S., Liu, Q., Battiston, R., De Santis, A., Liu, T., Tramutoli, V., Conti, L., and Yan, R.: 6 years results of EQ precursors research by using CSES-01 onboard and the following step of  IMCP , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3264, https://doi.org/10.5194/egusphere-egu24-3264, 2024.

part 2 Chairpersons: Pier Francesco Biagi, Xuhui Shen, Lixin Wu
11:40–11:50
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EGU24-6001
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On-site presentation
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Hans Eichelberger, Mohammed Y. Boudjada, Konrad Schwingenschuh, Bruno P. Besser, Daniel Wolbang, Maria Solovieva, Pier F. Biagi, Patrick H. M. Galopeau, Ghulam Jaffer, Christoph Schirninger, Aleksandra Nina, Gordana Jovanovic, Giovanni Nico, Manfred Stachel, Özer Aydogar, Cosima Muck, Josef Wilfinger, Irmgard Jernej, and Werner Magnes

Strong natural hazards together with their societal impact are usually accompanied by multiple physical phenomena which can be an important information source about the underlying processes.  
In this study we statistically analyze the lithosphere–atmosphere–ionosphere couplings of magnitude Mw5.5+ earthquakes (EQs) in the year 2023 with the aid of sub-ionospheric VLF/LF radio links. The electric field amplitude and phase measurements with a temporal resolution of one second are from the seismo-electromagnetic receiver facility in Graz (GRZ), Austria (Galopeau et al., 2023), which is part of the INFREP network. The spatial extend of the study area has the range [-10°E ≤ longitude ≤ 40°E] and [20°N ≤ latitude ≤ 50°N], in total are 17 EQs according to the United States Geological Survey (USGS) data base, among them the Turkey–Syria EQs (main shocks Mw7.8 and Mw7.5) and the Morocco Mw6.8 EQ. We apply the night-time amplitude method (Hayakawa et al., 2010) for all available paths, of particular importance are the transmitter links TBB (26.70 kHz, Bafa, Turkey), ITS (45.90 kHz, Niscemi, Sicily, Italy), and ICV (20.27 kHz, Tavolara, Italy). Relevant crossings are determined by the size of the Dobrovolsky-Bowman relationship (Dobrovolsky et al., 1979; Bowman et al., 1998).
A major finding is the statistically significant electric field variation of the TBB-GRZ link related to the Turkey–Syria EQ sequence. A physical interpretation is based on atmospheric gravity waves (AGWs) which could alter the E-layer in the lower ionosphere during nighttime and modulate the height of the waveguide cavity.

References:

Galopeau et al., A VLF/LF facility network for preseismic electromagnetic investigations, Geosci. Instrum. Method. Data Syst., 12, 231–237, 2023, https://doi.org/10.5194/gi-12-231-2023
Dobrovolsky et al., Estimation of the size of earthquake preparation zones, PAGEOPH 117, 1025–1044, 1979, https://doi.org/10.1007/BF00876083
Bowman et al., An observational test of the critical earthquake concept, JGR Solid Earth, 103, B10, 24359-24372, 1998, https://doi.org/10.1029/98JB00792
Hayakawa et al., A statistical study on the correlation between lower ionospheric perturbations as seen by subionospheric VLF/LF propagation and earthquakes, JGR Space Physics, 115(A9), 09305, 2010, https://doi.org/10.1029/2009JA015143

How to cite: Eichelberger, H., Boudjada, M. Y., Schwingenschuh, K., Besser, B. P., Wolbang, D., Solovieva, M., Biagi, P. F., Galopeau, P. H. M., Jaffer, G., Schirninger, C., Nina, A., Jovanovic, G., Nico, G., Stachel, M., Aydogar, Ö., Muck, C., Wilfinger, J., Jernej, I., and Magnes, W.: Investigation of VLF/LF electric field variations related to magnitude Mw≥5.5 earthquakes in the Mediterranean region for the year 2023, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6001, https://doi.org/10.5194/egusphere-egu24-6001, 2024.

11:50–12:00
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EGU24-10341
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On-site presentation
Mohammed Y. Boudjada, Pier Francesco Biagi, Hans Ulrich Eichelberger, Patrick H.M. Galopeau, Konrad Schwingenschuh, Maria Solovieva, Giovanni Nico, Helmut Lammer, Wolfgang Voller, and Manfred Stachel

We investigate the recent earthquakes (EQs) that occurred on 06 February 2023 principally in the central southern part of Turkey and north western of Syria. The tectonic plate movements between Anatolian, Arabian and African plates are well known to be subject to EQs. The coordinate of the epicenter was 37.08°E and 37.17°N with depth in the order of 10 km and a magnitude Mw7.8. Beside aftershocks, a few hours later a strong Mw7.7 earthquake occurred in the same region . We consider in this analysis the Bafa VLF transmitter (TBB) signal emitting at frequency of 26.7 kHz and localized in the Anatolia region (Turkey) at longitude of 27.31°E and latitude of 37.40°N. TBB transmitter signal is daily monitored by the VLF Graz facility (Biagi et al., 2019; Galopeau et al., 2023) with a sufficient signal to noise ratio principally during night observations. We study the variations of the phase and amplitude of TBB signals, as detected by Graz facility (15.43°E, 47.06°N) few weeks before the earthquakes occurrence. It is essential to note that the geographical latitudes of the epicenter and the TBB transmitter are about 37°N, and the distance, in the order of 850 km, is found smaller than the radius of the earthquake preparation zone, as derived from Dobrovolsky et al. (1979), when considering the magnitude of the seismic event, i.e. Mw7.8. We have applied the terminator time (TT) method to make evident the presence of sunrise and sunset time shifts at terminators one week to ten days before EQs.  We discuss essentially the anomalies, in the phase and the amplitude of TBB transmitter, which are probably linked to the electron density variations at the formation and the destruction of the ionospheric D-E-layers.

 

References:

Biagi et al., The INFREP Network: Present Situation and Recent Results, Open J. Earth. Research, 8, 2019.

Dobrovolsky et al., Estimation of the size of earthquake preparation zones, Pageoph, 117, 1979.

Galopeau et al., A VLF/LF facility network for preseismic electromagnetic investigations, Geosci. Instrum. Method. Data Syst., 12, 2023.

How to cite: Boudjada, M. Y., Biagi, P. F., Eichelberger, H. U., Galopeau, P. H. M., Schwingenschuh, K., Solovieva, M., Nico, G., Lammer, H., Voller, W., and Stachel, M.: Study of VLF phase and amplitude variations before the Turkey Syria Mw 7.8 EQs, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10341, https://doi.org/10.5194/egusphere-egu24-10341, 2024.

12:00–12:10
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EGU24-360
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ECS
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On-site presentation
Shreeja Das and Vladimir Frid

The Fracture-Induced Electromagnetic Radiation (FEMR) phenomenon has been substantially investigated as a prolific geophysical tool and provided a precursor to geohazards such as landslides, earthquakes, and rockburst hazards. Several lab-scale experiments on materials such as chalk, rocks, glass, ceramics, granite, etc., have been conducted to correlate between experimental observations and theoretical formulations of the physical parameters of FEMR generations such as crack dimensions, crack velocity, frequency of crack propagation, and finally draw an analogy with earthquake events. The FEMR working principle for Earth’s fracture detection is based on generating geogenic electromagnetic radiation from the brittle rock bodies subjected to differential stress in the near-surface of the Earth’s crust. When external stimuli, such as significant deviatoric stresses in thrust or shear zones due to active tectonic forces, induce stress on these rock bodies, microcracks form and propagate. The "Process zone" at the crack tip contains numerous microcracks and dipoles that emit FEMR waves in the kHz to MHz frequency range. As microcracks coalesce and lead to macro failure, the amplitude of FEMR pulses diminishes. FEMR pulses show less attenuation than seismic waves, making them a more efficient precursor to potential tectonic activities. They are an early warning sign for earthquakes a few hours or days before the event. The current study consisted of FEMR surveys along a segment of the active Dead Sea transform (DST) from Sodom to Jericho. This coincided with a 6.3 magnitude (Mw) aftershock earthquake (EQ) in the Turkey-Syrian region on February 20, 2023, where the last measurement was taken 2 hours before the EQ. Several FEMR parameters (e.g., Benioff strain release, frequency, rise time, hits or activity, and energy) along with their associated crack dimensions were analyzed after filtering the raw data and comprehending their trends leading up to the EQ. This study investigated the Benioff Strain plot and other parameters in three consecutive stages of earthquake nucleation leading to the EQ. In the first stage, there's an increase in FEMR hits and frequency, accompanied by a decrease in rise time (T') and crack dimensions. The second stage is characterized by a decline in FEMR hits and crack width while all continue to increase. Notably, the second stage accumulates the second highest energy, likely due to a high-stress drop. The third stage features a steady increase in FEMR hits and energy and an abnormal increase in crack dimensions, perhaps signifying an upcoming event of macro failure. The cyclic trend in FEMR hits suggests periods of high activity and silence, possibly related to stress changes during crack propagation. Because the measurements were taken a few hours before the earthquake, this survey provides valuable insights into the modulation of FEMR parameters before an earthquake. The results obtained from this analysis could bridge the gap between lab-scale and large-scale studies of stress-induced rock collapses and provide a befitting precursor to such disastrous natural calamities.

How to cite: Das, S. and Frid, V.: The Fracture Induced Electromagnetic Radiation (FEMR) induced along the Dead Sea Transform fault before the Syrian-Turkey earthquake (Mw-6.3) on 20.2.2023, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-360, https://doi.org/10.5194/egusphere-egu24-360, 2024.

12:10–12:20
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EGU24-13277
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On-site presentation
Patrick Galopeau, Mohammed Boudjada, Hans Eichelberger, Ashanthi Maxworth, Pier Biagi, and Konrad Schwingenschuh

We present a system which records electromagnetic signals, in the Very Low Frequency (VLF: 3 kHz – 30 kHz) and Low Frequency (LF: 30 kHz – 300 kHz) range, 24 x 7 x 365, with the goal of identifying ionospheric variations. An individual system consists of a monopole antenna, a pre-amplifier, a power supply, a central computer, a GPS unit, and a recording device. Several receivers will be implemented around the globe in a network. The first implementation of the system was done in Graz (Austria), the second one will be in Guyancourt (France), a third one in Réunion (France) and a fourth one in Moratuwa (Sri Lanka). Each reception device will allow a continuous daily monitoring of transmitter signals in the VLF and LF frequency bands. This network will be devoted to the study of ionospheric variations, in particular, those linked to the solar activity, but also those associated with seismic activity with the purpose to identify electromagnetic earthquake precursors.

How to cite: Galopeau, P., Boudjada, M., Eichelberger, H., Maxworth, A., Biagi, P., and Schwingenschuh, K.: Study of ionospheric variations from a global network of VLF antennas, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13277, https://doi.org/10.5194/egusphere-egu24-13277, 2024.

12:20–12:30
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EGU24-6407
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solicited
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Highlight
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On-site presentation
Dimitar Ouzounov, Sedat Inan, Pavel Kalenda, Libor Neumann, Sergey Pulinets, Jann-Yenq Liu, Xuhui Shen, Rui Yan, Jana Rušajová, Menas C. Kafatos, and Patrick Taylor

We study critical lithosphere/atmosphere /ionosphere coupling processes that precede earthquake events. Soon after the M7.8 and M7.5 in Kahramanmaraş, Türkiye on Feb 6, 2023, Kahramanmaraş earthquakes, we started collecting and processing multi-parameter data from ground, atmosphere, and satellite observations, such as 1/ Vertical static pendulums data from the European network; 2/ Hydrogeochemical data for electrical conductivity and major ion contents from the spring water samples near Kahramanmaraş ; 3/ Outgoing long-wavelength radiation (OLR) obtained from satellites NPOESS; 4/ Ionospheric plasma observations from China/Italy Seismo-Electromagnetic Satellite (CSES1);5/Electron density variations in the ionosphere via GPS Total Electron Content (GPS/TEC) and 6/ Atmospheric chemical potential (ACP) obtained from NASA assimilation models. We have detected two temporal groups of pre-earthquake anomalies: A/few months in advance - hydrogeochemical anomalies lasting up to six months and vertical static pendulums lasting two months ahead of the seismic rupture and B/few days in advance -  OLR and ACP anomalies showed an abnormal increase on Jan 15-30, along with the plasma electron and oxygen ion density from the CSES1 satellite which is highly correlated with electron density variations in the ionosphere from GPS/TEC. Two groups of identified anomalies relate to different stages of Kahramanmaraş earthquake preparation processes. The first type was linked to the crustal deformation phase and was associated primarily with the coupling processes of the lithosphere-atmosphere. Based on the cross-event analysis of major seismicity in the regions, we found similarities in the pre-earthquake pattern occurrence between the M7.8/M7.5 2023 Kahramanmaraş sequence and the M7.2 Van Earthquake of 2011 and two other major events.

We show that we could extract new information about the different stages of earthquake preparation processes by combining ground and near-space data according to the physical concept of LAIC.

How to cite: Ouzounov, D., Inan, S., Kalenda, P., Neumann, L., Pulinets, S., Liu, J.-Y., Shen, X., Yan, R., Rušajová, J., Kafatos, M. C., and Taylor, P.:  Multi-parameter study of the pre-earthquake phase associated with the Kahramanmaraş sequence in Türkiye on February 6th, 2023. , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6407, https://doi.org/10.5194/egusphere-egu24-6407, 2024.

Posters on site: Fri, 19 Apr, 16:15–18:00 | Hall X4

Display time: Fri, 19 Apr, 14:00–Fri, 19 Apr, 18:00
Chairpersons: Mohammed Y. Boudjada, Jing Cui
X4.63
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EGU24-11940
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solicited
Alejandro Ramírez-Rojas, Elsa Leticia Flores-Márquez, and Leonardo Di G. Sigalotti

The Mexican Pacific coast has presented significant seismic activity due to the tectonic processes that have generated it. This coast, from Baja California until Chiapas is matched with three tectonic settings, to the north, a dispersion zone is presented in Baja California and Cortes Sea, at the middle, conforming by Jalisco, Colima and Michoacan states, La Rivera Plate is the principal source of seismicity and, finally the seismic activity in Guerrero, Oaxaca and Chiapas is driven by the Cocos Plate subduction. According with the catalogues published by the SSN, the yearly number of earthquakes occurred is very different at each zone is very different being Cocos plate the subduction zone that has produced the major number of earthquakes. We analyzed the catalogues of six zones of the Mexican Pacific coast in the period between 2000 and 2023. Based on the Tsallis q-statistical approach it is possible to assess the temporal changes of the non-extensivity by fitting the cumulative number of earthquakes with the generalized Gutenberg-Richter. Our preliminary results show differences in the fitting of the q-values for the six studied regions. These results are consistent with a pervious analysis, where it was observed that the highest q-value was obtained in Jalisco zone, while Oaxaca region reported the lowest q-value.

How to cite: Ramírez-Rojas, A., Flores-Márquez, E. L., and Sigalotti, L. D. G.: Non-extensivity study of the seismicity along the Mexican Pacific coast based on the Tsallis q-statistical approach., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11940, https://doi.org/10.5194/egusphere-egu24-11940, 2024.

X4.64
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EGU24-18372
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ECS
Roberto Colonna, Carolina Filizzola, Nicola Genzano, Mariano Lisi, Nicola Pergola, and Valerio Tramutoli

After more than 25 years of studies it is possible to draw a balance of the efforts, based on the application of Robust Satellite Techniques to long-term satellite TIR (Thermal InfraRed) radiances, to identify (isolating them from all the others possible sources) those anomalies (in the spatial/temporal domain) possibly associated to the occurrence of major earthquakes.

The results achieved by processing multi-annual (more than 10 years) time series of TIR satellite images collected in different continents and seismic regimes, showed that more than 67% of all identified (space-time persistent) anomalies occur in the pre-fixed space-time window around the occurrence time and location of earthquakes (M≥4), with a false positive rate smaller than 33%. Moreover, Molchan error diagram analysis gave a clear indication of non-casualty of such a correlation, in comparison with the random guess function.

Here, we will critically discuss the results up to now achieved by applying long-term RST analyses in different part of the world. Moreover, we will also discuss the common and/or peculiar elements of success/failure respect to the possibility to build and implement a multi-parametric system for a time‐Dependent Assessment of Seismic Hazard (t‐DASH).

How to cite: Colonna, R., Filizzola, C., Genzano, N., Lisi, M., Pergola, N., and Tramutoli, V.: Robust Satellite Techniques for seismic prone area monitoring: recent achievements and future perspective toward a multi-parametric t‐DASH system, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18372, https://doi.org/10.5194/egusphere-egu24-18372, 2024.

Posters virtual: Fri, 19 Apr, 14:00–15:45 | vHall X4

Display time: Fri, 19 Apr, 08:30–Fri, 19 Apr, 18:00
Chairpersons: Hans Eichelberger, Carolina Filizzola
vX4.14
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EGU24-6275
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solicited
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Michael E. Contadakis, Christos Pikridas, Styllianos Bitharis, and Emmanuel Scordilis

This paper is one of a series of papers dealing with the investigation of the Lower ionospheric variation on the occasion of an intense tectonic activity.In the present paper, we investigate the TEC variations during the intense seismic activity in the transition between the Dead Sea fault and the East Anatolian fault (SE Turkey) on February 6th, 2023. The Total Electron Content (TEC) data are been provided by the EUREF Network. These data were analysed using Discrete Fourier Analysis in order to investigate the TEC turbulence band content. The results of this investigation indicate that the High-Frequency limit fo of the ionospheric turbulence content, increases as aproaching the occurrence time of the earthquake, pointing to the earthquake epicenter, in accordane to our previous investigations. We conclude that the Lithosphere Atmosphere Ionosphere Coupling, LAIC, mechanism through acoustic or gravity waves could explain this phenomenology.

 

Keywords: Seismicity, Lower Ionosphere, Ionospheric Turbulence, Brownian Walk, East Anatolian Fault.

 

How to cite: Contadakis, M. E., Pikridas, C., Bitharis, S., and Scordilis, E.: TEC variation over Europe during the intense tectonic activity in the area of SE Turkey on February of 2023., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6275, https://doi.org/10.5194/egusphere-egu24-6275, 2024.

vX4.15
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EGU24-8894
Iren Adelina Moldovan, Victorin Emilian Toader, Andrei Mihai, Alexandru Marmureanu, and Constantin Ionescu

Our study analyzes the possibility to include geophysical parameters in the existing OEF (Operational Earthquake Forecasting) application based on the geochemical detected anomalies correlated with short-term changes in seismicity rates and occurrence of medium sized intermediate depth earthquakes.

The study aims to decide which of the geomagnetic anomalous signals can be considered to be a reliable precursor of Vrancea, Romania moderate sized earthquakes that occurred in the last decade. The anomalies were observed using different processing methods: polarization, diurnal variation, differential analysis between two stations or simple visualization at only one station and the standard deviation from the mean value.

The existing OEF application for the Vrancea area based on geochemical parameters is using the standard deviation, time gradient, cross correlation, and linear regression customized for the geological specificity of the area under investigation. For anomaly detection is used the short-time-average through long-time-average trigger (STA/LTA) method on time-integral data. The daily–seasonal variation of parameters is correlated with atmospheric conditions and temperature in the borehole to avoid false decisions. The probability and epistemic uncertainty of the gas emissions act as input into a logical decision tree.

During the study period, in Vrancea seismogenic zone there have been recorded 25 earthquakes with moment magnitude Mw>4.5, at intermediate depth. The Geomagnetic data are obtained from Muntele Rosu (MLR) Seismological Observatory and Plostina (PLOR) of NIEP, situated inside Vrancea seismogenic zone as primary station, and from Surlari (SUA) National Geomagnetic Observatory, part of the International Real-time Magnetic Observatory (Intermagnet), as remote station, unaffected by medium size earthquake preparedness processes. We have assumed that the zone of effective manifestation of the precursor deformations is a circle with the radius taken from the equation of Dobrovolsky, 1979.  Geomagnetic indices taken from GFZ (https://www.gfz-potsdam.de/kp-index) were used to separate the global magnetic variation from possible local seismo-electromagnetic anomalies, that might appear in a seismic area like Vrancea zone and to ensure that observed geomagnetic fluctuations are not caused by solar-terrestrial effect.

Acknowledgments: This paper was carried out within AFROS Project PN-III-P4-ID-PCE-2020-1361, 119 PCE/2021, supported by UEFISCDI, Nucleu Program SOL4RISC, supported by MCI, project no PN23360201, and PNRR- DTEClimate Project nr. 760008/31.12.2023, Component Project Reactive, supported by Romania - National Recovery and Resilience Plan

How to cite: Moldovan, I. A., Toader, V. E., Mihai, A., Marmureanu, A., and Ionescu, C.: Attempts to include geomagnetic anomalies into the existing Romanian Operational Earthquake Forecast, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8894, https://doi.org/10.5194/egusphere-egu24-8894, 2024.

vX4.16
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EGU24-2942
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ECS
Abdennasser Tachema

This study investigates the early seismo-ionospheric signals preceding the 7.8 magnitude Turkey earthquake sequence on February 6, 2023. The main shock struck at 01:17:35 UTC in Şehitkamil, Gaziantep in southern Turkey near the northern border of Syria. About nine hours later, a strong 7.5 magnitude aftershock occurred to the northeast of the first main quake.

The present work is based on the analysis of the ionospheric behavior in response to these successive major earthquakes, using space-based GPS/GNSS (Global Positioning System/Global Navigation Satellite Systems) data. Employing geodetic data derived from both Turkish national (TUSAGA) and international (IGS) permanent receivers, we generated a local ionospheric map covering the seismogenic zone of southern Turkey. The aim is to reconstruct the time series of ionospheric Total Electron Content (TEC) and discern any potential anomalies in this signal. The diurnal variation of the ionospheric TEC shows homogeneity in the spatiotemporal pattern of the GNSS_TEC signal, except for January 12, 2023. At noon on this day, the ionospheric TEC reaches its maximum value (98.41 TECu), exceeding 250% of the mean value in the temporal series. This anomalous behavior prompted application of a robust statistical approach to exclude outliers, combined with wavelet transform analysis to capture the time-frequency characteristics of the ionospheric responses. These steps validated the results, indicating a potential seismic influence on the ionosphere approximately three weeks before the mainshock.

This research represents an important step to understanding seismo-ionospheric interactions, highlighting the complex relationship between crustal motions and ionospheric dynamics. Anomalies identified in the ionosphere prior to the major seismic event in Turkey suggest that the approach developed could be promising for predicting earthquakes. Further validation and collaboration are essential to refine these results and advance seismic risk assessment.

Keywords: 2023 Turkey earthquake, GPS/GNSS-TEC data, Pre-earthquake ionospheric anomaly, Crustal-Ionospheric Synergy.

How to cite: Tachema, A.: Exploring early seismo-ionospheric signs preceding the February 6, 2023, Turkey earthquake (Mw 7.8): Preliminary results, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2942, https://doi.org/10.5194/egusphere-egu24-2942, 2024.

vX4.17
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EGU24-6729
Analysis of the  mode interference  of Very Low-Frequency Electromagnetic Waves during Seismic Events
(withdrawn)
Andrea Inés Borgazzi, Enrique Carrasco, and Alejandro Lara
vX4.18
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EGU24-8281
Angelo De Santis, Homayon Alimorady, and Habib Rahimi

 Before the occurrence of an earthquake and when the lithosphere is in a state of critical stress accumulation, the lithosphere could react- with the so-called earthquake precursors. One of these precursors is the magnetic field, which, under proper conditions, may produce anomalies due to accumulated stress in the crust before an earthquake occurs. Since several years ago, it has been possible to observe the Earth's magnetic field through satellites. The Swarm satellite mission of the European Space Agency was launched at the end of 2013. It is composed of three identical specialized satellites for observing the Earth's magnetic field. Here, using the magnetic measurements provided by Swarm satellites, we investigate the possibility of identifying several anomalous magnetic signals before the occurrence of earthquakes, which are possibly related to lithosphere-atmosphere-ionosphere coupling. In this study, the earthquakes with a magnitude greater than 5.0 occurred from 2014 to 2023 in the Alpine-Himalayan belt under geomagnetically quiet conditions were examined. Using the algorithm applied to the data from 10 days before the earthquake, obvious anomalies in the components of the magnetic field are identified. Furthermore, a significant relationship between the length (duration) of the anomaly and the magnitude of the earthquake was observed and the empirical relationship between them was estimated. For instance, with the enhancement in the magnitude of the earthquake, the duration of the anomaly also increases.

In addition, significant relationships are also found between other parameters and the magnitude of the earthquake with an acceptable correlation.

We also performed a confutation analysis synthetizing a random catalogue of earthquakes and made again the correlation with the satellite anomalies: the results were far different from those obtained with real data, so confirming the validity of those results.

How to cite: De Santis, A., Alimorady, H., and Rahimi, H.: Potential earthquake precursory pattern of large Alpine- Himalayan earthquakes as seen by magnetic Swarm satellites, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8281, https://doi.org/10.5194/egusphere-egu24-8281, 2024.

vX4.19
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EGU24-13546
Busheng Xie, Lixin Wu, and Wenfei Mao

Among many precursors related with geology, geophysics and geochemistry field, the geomagnetic field is one of the most sensitive factors of seismic activity. Current works basically analyzed scalar values of multiple components separately or the ratio of vertical component and horizontal component to extract electromagnetic radiation anomalies in different frequency range. However, the relationship of induced magnetic horizontal vector (IMHV) and earthquake light generated by pressure-simulated rock current (PSRC) was initially proved in M7.3 Fukushima earthquake of 16 March 2022. The geomagnetic anomalies obtained by current methods originate from alternating electromagnetic fields instead of rock current, which lack the investigation of the direction information of seismic geomagnetic disturbance vector. 
By combining observational evidence from existing rock current experiments with the volumetric scaling effect, the intensity of current generated by the compressed crustal rock mass in seismogenic areas was estimated to be over 1 MA when the magnitude reaches 7 or above. Based on Biot-Savart's law, the magnetic field disturbance intensity generated by the rock current in three-dimensional space was simulated in this study. The simulation results indicate that magnetic field disturbances ranging from several nanotesla to tens of nanotesla can be generated at approximately 600 km from the rock current, which can be easily captured by the existing dense distribution of ground-based observatory networks (e.g., INTERMAGNET, MAGDAS).
This paper aims to propose an analysis method based on seismic geomagnetic disturbance vectors and validate it using the 2007 M7.3 Peru earthquake as a case study. In this method, two arbitrary geomagnetic stations around the seismogenic area are selected to obtain the magnetic variation of multiple geomagnetic component (e.g., declination horizontal, and vertical component), which are then synthesized into the disturbance vectors. Subsequently, the intersection line of the two vector planes of the magnetic field disturbances is determined based on the concept of forward intersection, allowing for an approximate estimation of the orientation of the rock current. Finally, the spatial relationship between multiple disturbance vectors and the rock current is assessed to determine if Biot-Savart's law is satisfied.
Taking the 2007 Peru earthquake as a research case, magnetic anomalies in both horizontal and vertical components were detected prior to the earthquake at two geomagnetic stations (i.e., the HUA station from INTERMAGNET and the ANC station from MAGDAS) located within 300 km from the epicenter. The method proposed in this study was utilized to further analyze the data, revealing that the rock currents obtained from the disturbance vectors were distributed around the seismogenic area. Besides, the combination of geological data and the positive holes theory also provided confirmation of the presence of rock types capable of generating current carriers in the seismogenic area. The method proposed in this study, to a certain extent, can effectively verify the spatiotemporal correlation between geomagnetic anomalies and seismic activities, which enables the localization of stress-locked regions and can serve as an effective approach for detecting seismic magnetic anomalies and short-term earthquake forecasting.

How to cite: Xie, B., Wu, L., and Mao, W.: New analysis method of seismic geomagnetic disturbance vector using ground-based observation: a case study of the 2007 Peru earthquake, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13546, https://doi.org/10.5194/egusphere-egu24-13546, 2024.

vX4.20
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EGU24-14043
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solicited
Xuemin Zhang, Angelo De Santis, Jing Liu, Saioa Campuzano, Na Yang, Serena D’Arcangelo, Xinyan Ouyang, Mariagrazia De Caro, Gianfranco Cianchini, Muping Yang, Cristiano Fidani, Xinyan Li, Martina Orlando, Hong Liu, Loredana Perrone, Lei Nie, Alessandro Piscini, Dario Sabbagh, and Maurizio Soldani

Due to the significant earthquake-related perturbations observed in the ionosphere by ground-based stations and space-borne satellites, scientists have increasingly focused on the studying the possible coupling mechanism among lithosphere, atmosphere and ionosphere. In this work, we contribute to this research, analyzing the phase of preparation of the 2022 Ms6.8 Luding (China) earthquake with a multi-parameter and multi-level approach from ground and satellite data taken in lithosphere, atmosphere and ionosphere, including the b value, earth resistivity, ELF magnetic field emissions, atmospheric electric field, surface temperature, foF2 from Ionosonde, GNSS TEC, magnetic field and electron density from CSES and Swarm satellites, etc. The results are encouraging confirming a chain of processes starting from ground and proceeding to the above atmosphere and ionosphere.

How to cite: Zhang, X., De Santis, A., Liu, J., Campuzano, S., Yang, N., D’Arcangelo, S., Ouyang, X., De Caro, M., Cianchini, G., Yang, M., Fidani, C., Li, X., Orlando, M., Liu, H., Perrone, L., Nie, L., Piscini, A., Sabbagh, D., and Soldani, M.: Lithosphere-atmosphere-ionosphere coupling processes for 2022 Luding Ms6.8 earthquake in China, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14043, https://doi.org/10.5194/egusphere-egu24-14043, 2024.