Studying the Impact of the Geospace Environment on Solar Lithosphere Coupling and Earthquake Activity

In solar–terrestrial physics, there is an open question: does a geomagnetic storm affect earthquakes? We expand research in this direction, analyzing the seismic situation after geomagnetic storms (GMs) accompanied by the precipitation of relativistic electrons from the outer radiation belt to form an additional radiation belt (RB) around lower geomagnetic lines. We consider four widely discussed cases in the literature for long-lived (weeks, months) RBs due to GMs and revealed that the 1/GMs 24 March 1991 with a new RB at L~2.6 was followed by an M7.0 earthquake in Alaska, 30 May 1991, near footprint L = 2.69; the 2/GMs 29 October 2003 (Ap = 204) with new RB first in the slot region at L = 2–2.5 cases followed by an M7.8 earthquake on 17 November 2003 at the Aleutian Islands near footprint L = 2.1, and after forming an RB at L~1.5 which lasted for ~26 months, two mega quakes, M9.1 in 2004 and M8.6 in 2005, occurred at the globe; the 3/GMs 3 September 2012 with a new RB at L= 3.0–3.5 was followed by an M7.8 earthquake in Canada near footprint L = 3.2; and the 4/GMs 21 June 2015 with a new RB at L = 1.5–1.8 was followed by an M6.3 earthquake on 7 September 2015 in New Zealand, near footprint L = 1.58. The obtained results suggest that (1) major earthquakes occur near the footprints of geomagnetic lines filled with relativistic electrons precipitating from the outer radiation belt due to geomagnetic storms, and (2) the time delay between geomagnetic storm onset and earthquake occurrence may vary from several weeks to several months. The results may expand the framework for developing mathematical magnetosphere–ionosphere coupling models

Two-photon laser scanning fluorescence microscopy using photonic crystal fibre

We report the application of a simple yet powerful modular pulse compression system, based on photonic crystal fibres which improves upon incumbent twophoton laser scanning fluorescence microscopy techniques. This system provided more than a 7-fold increase in fluorescence yield when compared with a commercial two-photon microscopy system. From this, we infer pulses of infrared radiaton of less than 35 fs duration reaching the sample

Atmosphere-Ionosphere Response to the M9 Tohoku Earthquake Revealed by Joined Satellite and Ground Observations. Preliminary results

The recent M9 Tohoku Japan earthquake of March 11, 2011 was the largest recorded earthquake ever to hit this nation. We retrospectively analyzed the temporal and spatial variations of four different physical parameters - outgoing long wave radiation (OLR), GPS/TEC, Low-Earth orbit tomography and critical frequency foF2. These changes characterize the state of the atmosphere and ionosphere several days before the onset of this earthquake. Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting on this day in the lower ionospheric there was also confirmed an abnormal TEC variation over the epicenter. From March 3-11 a large increase in electron concentration was recorded at all four Japanese ground based ionosondes, which return to normal after the main earthquake. We found a positive correlation between the atmospheric and ionospheric anomalies and the Tohoku earthquake. This study may lead to a better understanding of the response of the atmosphere /ionosphere to the Great Tohoku earthquakeComment: Preliminary results reported at EGU 2011 in Vienna, Austri

From Hector Mine M7.1 to Ridgecrest M7.1 Earthquake. A Look from a 20-Year Perspective

The paper provides a comparative analysis of precursory phenomena in the ionosphere and atmosphere for two strong earthquakes of the same magnitude M7.1 that happened in the same region (North-East from Los Angeles) within a time span of 20 years, the Hector Mine and Ridgecrest earthquakes. Regardless of the similarity of their location (South-Eastern California, near 160 km one from another), there was one essential difference: the Hector Mine earthquake happened during geomagnetically disturbed conditions (essential in the sense of ionospheric precursors identification). In contrast, the quiet geomagnetic conditions characterized the period around the time of the Ridgecrest earthquake. The Hector mine earthquake happened in the middle of the rising phase of the 23-rd solar cycle characterized by high solar activity, while the Ridgecrest earthquake happened by the very end of the 24th cycle under very low solar activity conditions. We provide a comprehensive multi-factor analysis, determine the precursory period for both earthquakes and demonstrate the close similarity of ionospheric precursors. Unlike the majority of papers dealing with earthquake precursor identification based on the “abnormality” of observed time-series mainly determined by amplitude difference between “normal” (usually climatic) behavior and “abnormal” behavior with amplitudes exceeding some pre-established threshold, we used the technique of cognitive recognition of the precursors based on the physical mechanisms of their generation and the morphology of their behavior during the precursory period. These permits to uniquely identify precursors even in conditions of disturbed environment as it was around the time of the Hector Mine earthquake. We demonstrate the close similarity of precursors’ development for both events. The leading time of precursor appearance for the same region and similar magnitude was identical. For the Hector Mine it was 11 October 1999—5 days in advance—and for 2019 Ridgecrest it was 28 June—7 days before the mainshock and five days before the strongest foreshock

Principles of Organizing Earthquake Forecasting Based on Multiparameter Sensor-WEB Monitoring Data

The paper describes an approach that allows, basing on the data of multiparameter monitoring of atmospheric and ionospheric parameters and using ground-based and satellite measurements, to select from the data stream a time interval indicating the beginning of the final stage of earthquake preparation, and finally using intelligent data processing to carry out a short-term forecast for a time interval of 2 weeks to 1 day before the main shock. Based on the physical model of the lithosphere-atmospheric-ionospheric coupling, the precursors are selected, the ensemble of which is observed only during the precursory periods, and their identification is based on morphological features determined by the physical mechanism of their generation, and not on amplitude selection based on statistical data processing. Basing on the developed maquette of the automatic processing service, the possibility of real-time monitoring of the situation in a seismically active region will be demonstrated using the territory of the Kamchatka region and the Kuril Islands

Editorial: Geospace Observation of Natural Hazards

This collection of technical papers aims to bring recent data from many sources into the study of natural hazards. They represent a multi-instrumental approach using both ground observations: Global Navigation Satellite System (GNSS); and Low Earth Orbiting Electromagnetic (LEO EM) satellites missions together with Earth Observations (EO), which could reveal new information. Results from latest satellite missions, [(NPP/NASA/NOAA(US), CENTINEL, Swarm/ESA (EU), HIMAWARI (JMA, Japan), FORMOSAT-5 (Taiwan, August 2017), CSES1 (China/Italy, Feb 2018), and FORMOSAT-7/COSMIC-2 (Taiwan/United States, May 2019)], are represented in this volume