Tectonic Processes in the Jan Mayen Fracture Zone Based on Earthquake Occurrence and Bathymetry

Sørensen, Mathilde B.; Ottemöller, Lars; Havskov, Jens; Atakan, Kuvvet; Hellevang, Bjarte; Pedersen, Rolf B.

doi:10.1785/0120060025

Cited by 11 publications

(6 citation statements)

References 27 publications

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“…The most recent compilation of earthquake focal mechanisms in Norway included 112 mechanisms and was presented by Hicks et al (2000a). Here, we present a new compilation of focal mechanisms in Norway including an additional three published mechanisms (Hicks & Ottemöller 2001;Ottemöller et al 2005;Sørensen et al 2007), seven previously unpublished mechanisms from the Norwegian National Seismic Network (Table 1) and seven mechanisms from the Global CMT Project (Ekström et al 2012). This new compilation of Norwegian focal mechanisms is, to the best of our knowledge, complete.…”

Section: Focal Mechanismsmentioning

confidence: 92%

A comparison of strain rates and seismicity for Fennoscandia: depth dependency of deformation from glacial isostatic adjustment

Keiding¹,

Kreemer

Lindholm

et al. 2015

Geophysical Journal International

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We investigate the influence of the glacial isostatic adjustment (GIA) on the deformation at the surface and at seismogenic depths in Fennoscandia. The surface strain rate field, derived from geodetic data, is controlled by GIA which causes NW-SE extension of up to 4 × 10 −9 yr −1 in most of mainland Fennoscandia, surrounded by regions of radial shortening towards the centre of uplift. The seismic deformation field, derived from a new compilation of focal mechanisms, shows consistent NW-SE compression on the Norwegian continental margin and a tendency towards tension in mainland Fennoscandia. The seismic moment rate is at least two orders of magnitude smaller than the geodetic moment rate. We propose that the low level of seismicity and the tendency towards tensional focal mechanisms in mainland Fennoscandia may be explained by the destructive interference of the regional stress from ridge push with the flexural stress due to GIA.

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Section: Focal Mechanismsmentioning

confidence: 92%

A comparison of strain rates and seismicity for Fennoscandia: depth dependency of deformation from glacial isostatic adjustment

Keiding¹,

Kreemer

Lindholm

et al. 2015

Geophysical Journal International

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“…Crampin, 1990), is not supported by the focal mechanisms of local earthquakes, as these dominantly result from strike-slip movements along the WJMFZ (Havskov and Atakan, 1991;Sørensen et al, 2007).…”

Section: Hodogram Analysismentioning

confidence: 99%

Vp/Vs-ratios and anisotropy on the northern Jan Mayen Ridge, North Atlantic, determined from ocean bottom seismic data

et al. 2015

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a b s t r a c tIn order to gain insight into the lithology and crustal evolution of the northern Jan Mayen Ridge, North Atlantic, the horizontal components of an Ocean Bottom Seismometer (OBS) dataset were analyzed with regard to Vp/Vs-modeling and seismic anisotropy. The modeling suggests that the northernmost part of the ridge consists of Icelandic type oceanic crust, bordered to the north by anomalously thick oceanic crust formed at the Mohns spreading ridge. The modeled Vp/Vs-ratios suggest variations in gabbroic composition and present-day temperatures in the area. Anisotropy analysis reveals a fast S-wave component along the Jan Mayen Ridge. This pattern of anisotropy is most readily interpreted as dikes intruded along the ridge, suggesting that the magmatism can be related to the development of a leaky transform since Early Oligocene.

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“…Significant tectonic activity along JMFZ is expressed by frequently occurring earthquakes on the island (Sørensen et al . 2007; Rodríguez‐Pérez & Ottemöller 2014).…”

Section: Settingmentioning

confidence: 99%

The last glaciation of the Arctic volcanic island Jan Mayen

Lyså

Larsen

Anjar

et al. 2020

Boreas

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The volcanic island of Jan Mayen, remotely located in the Norwegian‐Greenland Sea, was covered by a contiguous ice cap during the Late Weichselian. Until now, it has been disputed whether parts of the island south of the presently glaciated Mount Beerenberg area were ever glaciated. Based on extensive field mapping we demonstrate that an ice cap covered all land areas and likely also extended onto the shallow shelf areas southeast and east of the island. Chronological interpretations are based on K‐Ar and 40Ar/39Ar dating of volcanic rocks, cosmogenic nuclide (36Cl) surface exposure dating of bedrock and glacial erratics, and radiocarbon dating. We argue that ice growth started after 34 ka and that an initial deglaciation started some 21.5–19.5 ka in the southern and middle parts of the island. In the northern parts, closer to the present glaciers, the deglaciation might have started later, as evidenced by the establishment of vegetation 17–16 cal. ka BP. During full glaciation, the ice cap was likely thickest over the southern part of the island. This may explain a seemingly delayed deglaciation compared with the northern parts despite earlier initial deglaciation. In a broader context, the new knowledge of the Late Weichselian of the island contributes to the understanding of glaciations surrounding the North Atlantic and its climate history.

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Tectonic Processes in the Jan Mayen Fracture Zone Based on Earthquake Occurrence and Bathymetry

Cited by 11 publications

References 27 publications

A comparison of strain rates and seismicity for Fennoscandia: depth dependency of deformation from glacial isostatic adjustment

A comparison of strain rates and seismicity for Fennoscandia: depth dependency of deformation from glacial isostatic adjustment

Vp/Vs-ratios and anisotropy on the northern Jan Mayen Ridge, North Atlantic, determined from ocean bottom seismic data

The last glaciation of the Arctic volcanic island Jan Mayen

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