| Abstract Submission No. | ABS-3.1-0129 |
| Title of Abstract | A case study of the pre - seismic ionospheric response to 2021 Haiti Earthquake using ground and space-based observations |
| Authors | Sreeba Sreekumar*, G.Manju, Tarun. K. Pant |
| Organisation | Space Physics Laboratory (SPL), VSSC, ISRO |
| Address | Space Physics Laboratory, VSSC Trivandrum, kerala, India Pincode: 695022 E-mail: sreeba90@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | The detailed information about ionospheric anomalies associated with earthquakes are possible now due to the advent of various ground and space based ionospheric measurements. A strong Mw = 7.2 earthquake struck Haiti on August 14, 2021 at 12:29 UTC (18.434°N, 73.482°W, depth ∼10 km). This earthquake occurred as the consequence of oblique reverse motion along the Enriquillo-Plantain Garden fault zone (EPGFZ). In this study, the plausible pre-seismic variations in the ionosphere due to 2021 Haiti earthquake are examined using ground and space-based instruments. The daytime ionospheric response is analyzed using Vertical Total Electron Content (VTEC) from IGS stations and electron density from Swarm satellite data. Results demonstrate that bandpass filtered VTEC reveals clear, pronounced, pre - seismic oscillations of peak magnitudes of ~ 0.2 TECU on August 5 2021, i.e., 9 days before the earthquake for stations near and just outside the earthquake preparation zone. Similarly, enhanced wave-like oscillations are also evident in the filtered VTEC data near the conjugate stations on the same day. Another unique feature during August 5, 2021 is the anomalous enhancement of northern Equatorial Ionization Anomaly (EIA) crest shown by Swarm electron density data. Such an enhancement is not observed for other days during August. This is also concurrent with the drop in Relative humidity (RH) occurred during the same day near the impending epicenter region. Hence the concomitant anomalies found in various atmospheric and ionospheric parameters suggest that the anomalies found on August 05, 2021 is plausibly related to the Haiti 2021 earthquake. This study also sheds some light into similarities with the Haiti 2010 event which occurred very close to the epicenter of 2021 event, hence emphasizing the need of detailed study of the Earthquake prone regions of Haiti using multiple precursor parameters |
| Keywords | Haiti 2021 earthquake, GNSS TEC, Swarm satellite, earthquake precursors, ionospheric seismology |