The latest publication by the Seismic Monitoring and Research Group SMRG at UM is about the earthquakes that struck Malta in 2020 – An earthquake swarm on the Malta Graben, Central Mediterranean, September – November 2020
The paper is published on Xjenza Online [1] and in it SMRG discuss the earthquake sequence and the felt reports submitted through its website.
In an abstract from the paper, the SMRG of the University of Malta describe the seafloor of the Sicily Channel as characterised by an extensional regime governed by a network of normal and strike-slip fault systems.
It said that these faults generate a background level of seismicity that rarely exceeds magnitude 5.0. A number of these faults pass close to the Maltese islands.
SMRG said that in particular, the Malta graben lies less than 15km to the south of Malta at its closest point, and the islands have been shaken a number of times by earthquakes originating on this and other fault systems.
“In this study, we describe the occurrence of a seismic sequence that started in September 2020 and lasted for several weeks, the largest event having a local magnitude of 4.5 and being strongly felt throughout the archipelago,” the group said.
The sequence was located at a distance of around 23km south of the eastern tip of Malta. SMRG added, “we have used single-station polarisation analysis at seismic station WDD to estimate epicentral location for all events down to magnitude 1.2.”
“For the largest events, we have also used conventional network location, utilising phase picks at stations of the Malta Seismic Network and in Southern Sicily,” the group said.
SMRG describes in the paper the time evolution of the sequence, felt effects, the public response and the implications for seismic hazard.
The paper can be read in full following the link above.
Photo: SMRG