Analysis of geomagnetic Ap index on worldwide earthquake occurrence using the principal component analysis and hierarchical cluster analysis

Nur Hidayah Ismail, and Nazhatulshima Ahmad, and Nur Anisah Mohamed, and Mohammad Redzuan Tahar, (2021) Analysis of geomagnetic Ap index on worldwide earthquake occurrence using the principal component analysis and hierarchical cluster analysis. Sains Malaysiana, 50 (4). pp. 1157-1164. ISSN 0126-6039

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Official URL: https://www.ukm.my/jsm/malay_journals/jilid50bil4_...

Abstract

Geoeffective solar events, especially the coronal mass ejection (CME) and the high-speed solar wind (HSSW) will induce geomagnetic storm upon its arrival to Earth. The solar events could trigger an earthquake occurred during the arrival. In this study, the focus is on the proxy of the geoeffective solar events, which is the geomagnetic Ap index and the data of shallow worldwide earthquakes. The main objective was to investigate the impact of geomagnetic storms on the occurrences of earthquakes from 1994 to 2017 from a statistical perspective. The geomagnetic Ap index data was obtained from the Helmholtz-Centre Postdam - GFZ German Research Centre for Geosciences and the shallow worldwide earthquake data were from the United States Geological Survey (USGS) earthquake catalogue. The Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were used to analyse the data. Two groups were obtained from the PCA biplot: Group 1 - before the event (Day-4 to Day-1) and Group 2 - after the event group (Day 0 to Day+4). A two-cluster solution was obtained from the HCA, which shows that days before and after geostorm are divided into two main clusters. The statistical results show that earthquakes activity might have different behaviour before and after the geostorm occurred. In conclusion, the results emphasize that there are differences between days before and after the geostorm occurrence, hence, the solar influence upon earthquake occurrences cannot be neglected entirely.

Item Type:Article
Keywords:Ap index; Earthquake; Geomagnetic storm; Solar activity
Journal:Sains Malaysiana
ID Code:17187
Deposited By: ms aida -
Deposited On:22 Jul 2021 05:13
Last Modified:26 Jul 2021 03:22

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