The stratovolcano Beerenberg, is the northernmost active subaerial volcano on Earth.
The upper part of Beerenberg is covered by an ice cap, which sends glacial tongues in all directions.
Several of these are typical outlet glaciers and 5 of them calve into the sea, 2 on the eastern coast and 3 on the
northwestern coast.

The volcano forms the northern end of Jan Mayen Island, 550 km north-northeast of Iceland.
Jan Mayen is 53.6 km long and width is 2.5 - 15.8 km. It has an area of 380 km².
The island is less than 700,000 years old.
The southern part of the island is a mountainous ridge made of scoria craters, scoria mounds, and trachytic domes.

Map based on Imsland (1986)	Map based on Sylvester (1975)	Eruption areas 1970/1985

Beerenberg is in a fairly unusual tectonic setting near the intersection of the
Jan Mayen Fracture Zone (a transform fault) and the Mohns mid-ocean ridge.
The Kolbiensey Ridge is 170 km to the east.

Beerenberg has erupted six times between 1732 and 1985. All of these eruptions were on flank vents and produced
lava flows and scoria cones. The most recent eruptions were in 1970, 1973, and 1985.

The 1970 eruption began on September 18 and continued to January, 1971. Intense storms hid the onset of the eruption.
A commercial pilot spotted the eruption cloud on September 20.
It was the only historic eruption witnessed in modern times. The eruption was large, erupting at least 0.5 km³ of basalt
from a 6 km long fissure that ran from sea-level to an elevation of 1,000 m. There were at least five active craters.

Photos from the 1970 eruption


22-23 Sep. 1970
Photo: C.A.Gløersen


22-23 Sep. 1970
Photo: C.A.Gløersen

22-23 Sep. 1970
Photo: C.A.Gløersen

The 1985 eruption began on January 6, 1985 and lasted only 35-40 hours. In that brief time about 7 million m³ of lava
was erupted (enough to bury a football field in 1400 m of lava!).
Earthquakes, with magnitudes up to 5, occurred during the eruption. The eruption was thought to be from a leaky fracture zone not the Jan Mayen magma system proper (Imsland, 1986). The vent was 35 km from the settlement.

The Department of Earth Science, University of Bergen has operated seismic stations on Jan Mayen (as part of the
National Seismic Network of Norway) since 1961 http://www.geo.uib.no/Seismo/ The 3 stations on Jan Mayen
(Olonkin City , Ulla and Liberg) are use to make daily locations of the local seismicity as well as recording far away
earthquakes http://www.geo.uib.no/Seismo/nnsn/index.html The seismic network on Jan Mayen serves as an important
monitor of the activity of Beerenberg and surrounding area.

Also other field expeditions visited Jan Mayen in August 1973 in connection with search for magma chambers
beneath the island.
http://www.geol.ucsb.edu/faculty/sylvester/JAN%20MAYEN/JanMayenHome.html

NORSAR has been established as the Norwegian National Data Center (NDC) for treaty verification for the Comprehensive Nuclear-Test-Ban treaty (CTBT). Seismic datas are sent continiously from Jan Mayen to Norsar.
Here is last seismic activity at JMI.


Sentralkrateret
Photo: Stein Henrik Olsen - 2000
Top of Beerenberg, 2277m.asl

Source: Received from Øystein Magnus Tønnessen, Jan Mayen, - July 2013.

http://www.jan-mayen.no/