Strýtan vent field
| Strýtan Vent Field | |
|---|---|
.svg)  | |
| Location | Atlantic Ocean |
| Coordinates | 65°49′18″N 18°07′24″W / 65.82167°N 18.12333°W |
| Max. elevation | −70 metres (−230 ft) |
| Min. elevation | −16 metres (−52 ft) |
The Strýtan vent field is a hydrothermal vent field located in the northern Atlantic Ocean at a depth of 16–70 metres (52–230 ft). It is located within Iceland's northern fjord Eyjafördur near Akureyri.[1] As of 2024, it is the only known alkaline hydrothermal vent field hosted on basalt rock.[2]
It is a popular site for divers.
History
[edit]The oldest reports of the Strýtan vent field date back hundreds of years to fishermen using dive weights. However, the Icelandic Coast Guard did not detect the vent chimneys and declared them as non-existent in 1987.[3] Only in 1997 was the Strýtan vent field reported by divers Erlendur Bogason and Árni Halldósson and identified as a real geologic feature.[4] It was also explored by GEOMAR in 1997, using the HOV JAGO, a German research submersible.[5]
In 2001, Strýtan was designated as a protected Icelandic preserve.[6]
Geology and location
[edit]Strýtan is in the vicinity of the Dalvík Lineament, which connects to the Eyjafjarðaráll Rift which extends to the Kolbeinsey Ridge.[7] Strýtan is among the shallowest vent fields known and is among the few coastal hydrothermal systems known.
The vent field is composed of three primary venting sites. Big Strýtan, Arnarnesstrýtur (sometimes referred to as Little Strýtan), and Hrisey. The Big Strýtan cone is composed prodominantly of anhydrite and saponite, with some chimneys as tall as 55 metres (180 ft).[2][5][8] Samples from the site indicate an extensive series of mineral phases within the mounds with fibrous, crystalline minerals establishing pore spaces for fluids to travel through.[9]
Geochemistry
[edit]Unlike Lost City, another alkaline field to the south in the Atlantic, Strýtan is hosted on 6-12 MA Mid-ocean ridge basalts and recharge is primarily from freshwater contributions of terrestrial origin, with fluid stable isotopes (δ18O, δ2H) and radiocarbon matching that of terrestrial reservoirs.[2][10]
Venting fluids are moderate at a temperature of ~76 °C (169 °F) and are highly alkaline at a pH of about 10.2.[11] Venting is most profuse at Big Strýtan, where the discharge rate is estimated at 50 meters per second.[10] Silica, magnesium, calcium, and oxygen are abundant in venting fluids and salinity is 0.5 - 14% of that of seawater. Silicon dioxide concentrations are elevated relative to seawater and consume magnesium in the precipitation of tall saponite chimneys.
A 2024 study found brucite within the chimneys at Strýtan, suggesting the possibility of ferrobrucite (containing iron) and therefore prebiotic chemistry reactions like those seen at Lost City.[2]
Biology
[edit]
Strýtan has an abundance of mussels, bryozoans, sponges, hydroids, brittlestars, and polychete worms. Metridium anemones, nudibranchs, and sea spiders have also been reported.[12]
References
[edit]- ^ Twing, Katrina I.; Ward, L. M.; Kane, Zachary K.; Sanders, Alexa; Price, Roy Edward; Pendleton, H. Lizethe; Giovannelli, Donato; Brazelton, William J.; McGlynn, Shawn E. (17 November 2022). "Microbial ecology of a shallow alkaline hydrothermal vent: Strýtan Hydrothermal Field, Eyjafördur, northern Iceland". Frontiers in Microbiology. 13: 960335. doi:10.3389/fmicb.2022.960335. PMC 9713835. PMID 36466646.
- ^ a b c d Gutiérrez-Ariza, Carlos; Barge, Laura M.; Ding, Yang; Cardoso, Silvana S. S.; McGlynn, Shawn Erin; Nakamura, Ryuhei; Giovanelli, Donato; Price, Roy; Lee, Hye Eun; Huertas, F. Javier; Sainz-Díaz, C. Ignacio; Cartwright, Julyan H. E. (2024-02-29). "Magnesium silicate chimneys at the Strytan hydrothermal field, Iceland, as analogues for prebiotic chemistry at alkaline submarine hydrothermal vents on the early Earth". Progress in Earth and Planetary Science. 11 (1): 11. doi:10.1186/s40645-023-00603-w. ISSN 2197-4284.
- ^ "Strýtan". Strytan Divecenter.
- ^ Salvarezza, Michael; Weaver, Christopher (20 December 2023). "Strýtan: Diving Iceland's Hydrothermal Vents | X-Ray Mag". xray-mag.com. AquaScope Media ApS - Copenhagen.
- ^ a b Stoffers, P.; Botz, R.; Garbe-Schönberg, Dieter; Hannington, Mark D.; Hauzel, B.; Herzig, Peter; Hissmann, Karen; Huber, R.; Kristjansson, J. K.; Petursdottir, S. K.; Schauer, Jürgen; Schmitt, M.; Zimmerer, M.; Devey, Colin; Krienitz, M.; Lichowski, F.; Möller, H.; Pracht, J. (1997). "Cruise Report Poseidon 229a/b Kolbeinsey Ridge, Akureyri - Reykjavik". Geologisch-Paläontologisches Institut und Museum. doi:10.3289/CR_POS229 – via oceanrep.geomar.de.
- ^ "Dive Site Strýtan - DIVE.IS - Iceland". www.dive.is.
- ^ Rögnvaldsson, Sigurður T.; Gudmundsson, Agust; Slunga, Ragnar (10 December 1998). "Seismotectonic analysis of the Tjörnes Fracture Zone, an active transform fault in north Iceland". Journal of Geophysical Research: Solid Earth. 103 (B12): 30117–30129. doi:10.1029/98JB02789.
- ^ Price, Roy (9 February 2014). "The Strytan Hydrothermal Field (SHF), Eyjafjord, Iceland". SoMAS.
- ^ Stanulla, Richard; Stanulla, Christiane; Bogason, Erlendur; Pohl, Thomas; Merkel, Broder (December 2017). "Structural, geochemical, and mineralogical investigation of active hydrothermal fluid discharges at Strýtan hydrothermal chimney, Akureyri Bay, Eyjafjörður region, Iceland". Geothermal Energy. 5 (1): 8. doi:10.1186/s40517-017-0065-0. S2CID 34408874.
- ^ a b Marteinsson, Viggó Thór; Kristjánsson, Jakob K.; Kristmannsdóttir, Hrefna; Dahlkvist, Maria; Sæmundsson, Kristján; Hannington, Mark; Pétursdóttir, Sólveig K.; Geptner, Alfred; Stoffers, Peter (February 2001). "Discovery and Description of Giant Submarine Smectite Cones on the Seafloor in Eyjafjordur, Northern Iceland, and a Novel Thermal Microbial Habitat". Applied and Environmental Microbiology. 67 (2): 827–833. Bibcode:2001ApEnM..67..827M. doi:10.1128/AEM.67.2.827-833.2001. PMC 92654. PMID 11157250.
- ^ Barge, Laura M.; Price, Roy E. (December 2022). "Diverse geochemical conditions for prebiotic chemistry in shallow-sea alkaline hydrothermal vents". Nature Geoscience. 15 (12): 976–981. Bibcode:2022NatGe..15..976B. doi:10.1038/s41561-022-01067-1. S2CID 253794485.
- ^ GEORGIEVA, MAGDALENA. "Field Notes: Iceland's Shallow Hydrothermal Vents". fieldnotes.nationalgeographic.org.