The Norwegian island of Jan Mayen is situated north of Iceland. It might be the only place on earth where no one yet has bothered to find anything valuable. Except for a short stint in the early twentieth century when Norwegian trappers hunted polar bears and blue fox. Jan Mayen services as a combined polar research facility, meteorological post and radio station. The islands airstrip is also used as a point for air rescue services.
The location of the island gives Norway a large part of the Arctic. The Norwegian economic zone is counted from the eastern part of mainland Norway all the way to Jan Mayen. This “ownership” is becoming increasingly challenged today since large sub-aquatic oil and gas-fields are thought to be located there.
Jan Mayen is consisting of two connected areas. The northern is dominated by the towering Beerenberg strato-volcano that juts 2277 meters straight from the ocean. The southern end is elongated and rather flat.
The islands volcanic activity reminds quite a lot of the Icelandic. The island comes with its own hotspot, also named Jan Mayen, and the Island is placed on the Jan Mayen micro-continent. The micro-continent once belonged to the Greenland plate, but is welded to the Eurasian continental plate, right beside the Jan Mayen triple-rift spot on the North Atlantic Ridge, aptly named Jan Mayen of course. Jan Mayen is surrounded by about ten sub-aquatic volcanos, but very little is known about their level of activity.
Beerenberg volcano is a mainly basaltic strato-volcano with an abundance of parasitic cinder cones on its slopes. The volcano has had a period of heightened eruptive behavior that started in 1970 with a VEI-3 eruption that forced an evacuation of the island. Then another small eruption came in 1973 (VEI-1) and the latest 1985 (VEI-0). It is believed that the diminishing sizes of the eruptions is a sign that the volcano lost momentum, and might go dormant until the next eruption cycle starts again. The cycle dormancy length is normally roughly 100 to 150 years, so if that is true, it will be some time before an eruption occurs again.
The southern end of the island is consisting of the inactive Holocene rifting fissure volcano system of Sör-Jan. It is comprised of splatter cones and seems to have erupted in short fissures running along the length of the island and finally reaching quite far south of the island.
If I would speculate a bit here, the shape of the volcano more seems like a central volcano with a southward fissure swarm than two separate volcanoes. But this has to my knowledge not been scientifically tested.
A Karman Vortex Street is a fancy name for oscillating turbulence. It is when for instance wind goes around a flag-pole, and it start to alternate to go around on the left and then the right side. That creates a flag-pole that will start to vibrate and “sing”.
Beerenberg is a rather stupendous flag-pole due to its height and narrow top. The volcano sometimes slices apart passing clouds that get divided as they try to pass. And then the wind starts to the left, then back to the right, and so on back and forth. The result?
A Harman Vortex Street is one of nature’s most beautiful phenomena. Whoever said that theoretical physics can’t be beautiful when let loose in nature?
(Originally posted November 11, 2011)