DashboardNewsSwarmsM 7.0+
VolcanoesSupervolcanoesRegionsGlobal
Favorites
BlogAbout
Privacy PolicyDisclaimer
Follow
Note:This page contains AI-generated content for informational and entertainment purposes only. It may contain inaccuracies. Raw event data is from USGS and EMSC. All statistics, lists, and derived information are generated by this site. Full disclaimerFound an error?
Location:
STRAIT OF GIBRALTAR
Period:
15 Sep 2022 00:49:43 - 19 Sep 2022 02:32:57 (4 days 1 hour 43 minutes)
Volcanoes in 100km radius:
None
Earthquakes:
55
16 swarms found nearby.
2016
PS20160125.1(18.1km)
25 Jan
1 hours
6 earthquakes
2021
15 May
3 days 23 hours
51 earthquakes
6 Jun
11 days 1 hours
144 earthquakes
S20210730.3(22.7km)
29 Jul
57 days 9 hours
1361 earthquakes
S20211114.1(13.2km)
13 Nov
5 days 5 hours
78 earthquakes
20 Nov
5 days 9 hours
57 earthquakes
5 Dec
5 days 18 hours
57 earthquakes
20 Dec
10 days 0 hours
135 earthquakes
2022
5 Feb
8 days 15 hours
147 earthquakes
7 Apr
28 days 16 hours
392 earthquakes
19 May
21 days 19 hours
412 earthquakes
16 Jun
6 days 9 hours
74 earthquakes
19 Jul
22 days 3 hours
330 earthquakes
3 Oct
5 days 4 hours
91 earthquakes
15 Oct
5 days 23 hours
62 earthquakes
2024
15 Mar
2 days 2 hours
32 earthquakes
AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm S20220915.1 in the Strait of Gibraltar

The Strait of Gibraltar marks the narrow marine passage between the Iberian Peninsula and North Africa, situated at the convergent boundary between the African and Eurasian tectonic plates. This geologically dynamic zone experiences ongoing crustal deformation driven by the northwestward motion of the African plate relative to Eurasia at rates of approximately 4–6 mm per year. The resulting transpressional regime produces frequent low-to-moderate magnitude earthquakes, often clustered in swarms rather than isolated mainshock-aftershock sequences.

SeismoSight recorded swarm S20220915.1 beginning at 00:49 UTC on 15 September 2022 and concluding at 02:32 UTC on 19 September 2022. Over 97 hours and 43 minutes, the network detected 55 earthquakes within the designated Strait of Gibraltar polygon. Event depths ranged primarily between 2 km and 38 km, with the majority occurring in the upper crust between 5 km and 20 km. Magnitudes spanned 1.7 to 4.6, the largest event registering 4.6 at 10 km depth on 15 September at 21:05:51 UTC. A secondary 3.5 event occurred simultaneously at the same depth, followed minutes later by a 2.8 quake at 38 km.

Activity showed clear temporal clustering, with 24 events on 15 September alone, including the peak magnitude. Subsequent days recorded 18 events on 16 September, 9 on 17 September, 3 on 18 September, and a final event on 19 September. Depths exhibited modest variation, with shallower events (under 10 km) interspersed among deeper crustal shocks, consistent with fluid migration or stress transfer along pre-existing faults in the Gibraltar Arc system.

This swarm aligns with the region’s established seismic character. Since 1 January 2000, 13 swarms have been documented in the same area, distributed across 2016 (1 swarm), 2021 (7 swarms), and 2022 (5 swarms). Such recurrent swarm behavior reflects the complex fault network accommodating oblique convergence and possible aseismic slip contributions.

The 2022 sequence remained below levels that would generate significant ground shaking or tsunami risk in coastal communities on either side of the strait. Continued monitoring by regional networks provides essential data for refining seismic hazard models in this strategically important maritime corridor.

References
USGS Earthquake Catalog (earthquake.usgs.gov)
EMSC European Mediterranean Seismological Centre (emsc-csem.org)
IGN Instituto Geográfico Nacional Spain (ign.es)
SeismoSight internal classification records