... (1998), who focused on the geochemical standardis-ation of tephra glass shards during electro... more ... (1998), who focused on the geochemical standardis-ation of tephra glass shards during electronmicroprobe analyses. The quantification of sodium, especially in rhyolitic glass shards, has often been a problem during electron microprobe analysis, frequently resulting in a 50 ...
... Eiríksson, J., Knudsen, KL, Haflidason, H. and Heinemeier, J. (2000), Chronology of late Holo... more ... Eiríksson, J., Knudsen, KL, Haflidason, H. and Heinemeier, J. (2000), Chronology of late Holocene climatic events in the northern North Atlantic based on AMS 14 C dates and tephra markers ... The foraminiferal assemblages reflect a general cooling trend during the last 4600 yr. ...
... Print Version (2082432 bytes). EOS, TRANSACTIONS AMERICAN GEOPHYSICAL UNION, VOL. 85, NO. 31,... more ... Print Version (2082432 bytes). EOS, TRANSACTIONS AMERICAN GEOPHYSICAL UNION, VOL. 85, NO. 31, P. 293, 2004 doi:10.1029/2004EO310006. Did the Punctuated Demise of Glacial Ice in the North Sea Affect Thermohaline Circulation of the Ocean? Chris D. Clark. ...
The volcanic island Jan Mayen, located in the Norwegian–Greenland Sea, hosts the active stratovol... more The volcanic island Jan Mayen, located in the Norwegian–Greenland Sea, hosts the active stratovolcano of Beerenberg, the northernmost active subaerial volcano in the world. At least five eruptions are known from the island following its discovery in the 17th century, but its eruptive history prior to this is basically unknown. In this paper two sediment cores retrieved close to Jan Mayen have been studied in detail to shed light on the Holocene history of explosive volcanism from the Jan Mayen volcanic province. Horizons with elevated tephra concentrations were identified and tephra from these was analysed to determine major element chemistry of the tephra. The tephra chemistry was used to provide a link between the two cores and the land based tephra records from Jan Mayen Island. We managed to link two well-developed tephra peaks in the cores by their geochemical composition and age to Jan Mayen. One of these peaks represents the 1732 AD eruption of Eggøya while the other peak represents a previously undescribed eruption dated to around 10.3 ka BP. Two less prominent tephra peaks, one in each core, dated to approximately 2.3 and 3.0 ka BP, also have a distinct geochemical character linking them to Jan Mayen volcanism. However, the most prominent tephra layer in the cores located close to Jan Mayen and numerous other cores along the Jan Mayen ridge is the 12.1 ka BP Vedde Ash originating from the Iceland volcanic province. We find that the Holocene volcanism on Jan Mayen is much less explosive than volcanism in Iceland, and propose that either low amounts of explosive volcanic activity from the summit region of Beerenberg or small to absent glacier cover on Beerenberg is responsible for this.
... (1998), who focused on the geochemical standardis-ation of tephra glass shards during electro... more ... (1998), who focused on the geochemical standardis-ation of tephra glass shards during electronmicroprobe analyses. The quantification of sodium, especially in rhyolitic glass shards, has often been a problem during electron microprobe analysis, frequently resulting in a 50 ...
... Eiríksson, J., Knudsen, KL, Haflidason, H. and Heinemeier, J. (2000), Chronology of late Holo... more ... Eiríksson, J., Knudsen, KL, Haflidason, H. and Heinemeier, J. (2000), Chronology of late Holocene climatic events in the northern North Atlantic based on AMS 14 C dates and tephra markers ... The foraminiferal assemblages reflect a general cooling trend during the last 4600 yr. ...
... Print Version (2082432 bytes). EOS, TRANSACTIONS AMERICAN GEOPHYSICAL UNION, VOL. 85, NO. 31,... more ... Print Version (2082432 bytes). EOS, TRANSACTIONS AMERICAN GEOPHYSICAL UNION, VOL. 85, NO. 31, P. 293, 2004 doi:10.1029/2004EO310006. Did the Punctuated Demise of Glacial Ice in the North Sea Affect Thermohaline Circulation of the Ocean? Chris D. Clark. ...
The volcanic island Jan Mayen, located in the Norwegian–Greenland Sea, hosts the active stratovol... more The volcanic island Jan Mayen, located in the Norwegian–Greenland Sea, hosts the active stratovolcano of Beerenberg, the northernmost active subaerial volcano in the world. At least five eruptions are known from the island following its discovery in the 17th century, but its eruptive history prior to this is basically unknown. In this paper two sediment cores retrieved close to Jan Mayen have been studied in detail to shed light on the Holocene history of explosive volcanism from the Jan Mayen volcanic province. Horizons with elevated tephra concentrations were identified and tephra from these was analysed to determine major element chemistry of the tephra. The tephra chemistry was used to provide a link between the two cores and the land based tephra records from Jan Mayen Island. We managed to link two well-developed tephra peaks in the cores by their geochemical composition and age to Jan Mayen. One of these peaks represents the 1732 AD eruption of Eggøya while the other peak represents a previously undescribed eruption dated to around 10.3 ka BP. Two less prominent tephra peaks, one in each core, dated to approximately 2.3 and 3.0 ka BP, also have a distinct geochemical character linking them to Jan Mayen volcanism. However, the most prominent tephra layer in the cores located close to Jan Mayen and numerous other cores along the Jan Mayen ridge is the 12.1 ka BP Vedde Ash originating from the Iceland volcanic province. We find that the Holocene volcanism on Jan Mayen is much less explosive than volcanism in Iceland, and propose that either low amounts of explosive volcanic activity from the summit region of Beerenberg or small to absent glacier cover on Beerenberg is responsible for this.
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