Brown Bluff

Coordinates: 63°32′S 56°55′W / 63.533°S 56.917°W / -63.533; -56.917
Source: Wikipedia, the free encyclopedia.
Brown Bluff
Brown Bluff as seen from Antarctic Sound
Highest point
Elevation745 m (2,444 ft)[1]
ListingList of subglacial volcanoes
List of volcanoes in Antarctica
Coordinates63°32′S 56°55′W / 63.533°S 56.917°W / -63.533; -56.917[1]
Geography
Geology
Mountain typeTuya
Volcanic fieldJames Ross Island Volcanic Group
Last eruptionPleistocene

Brown Bluff is a

tuff cone, slope failure, and hyaloclastite delta; and into five structural units.[3]

The volcano gets its name from its steep slopes and brown-to-black hyaloclastite. It was applied by the

Falklands Islands Dependencies Survey following their survey in 1946.[1]

Environment

Topography

Brown Bluff has a 1.5 km-long (0.93 mi) cobble and ash beach rising increasingly steeply towards towering red-brown tuff cliffs embedded with bombs and tephra. The cliffs are heavily eroded, resulting in loose scree and rock falls on higher slopes, and large, wind-eroded boulders on the beach. Permanent ice and tidewater glaciers surround the site to the north and south, occasionally filling the beach with brash ice.

Flora and fauna

Lichens in the genera Xanthoria and Caloplaca have been recorded on exposed boulders from the shoreline to an elevation of 185 m (607 ft). Mosses occur at higher elevations near glacial drainage.

The site has been identified as an

gentoo penguins. Other birds nesting there include cape petrels, Wilson's storm petrels and kelp gulls.[4] Weddell seals regularly haul out, and leopard seals
often hunt offshore.

Geology

Brown Bluff is a one-half-mile-high (0.80 km) cliff of volcanic rocks consisting of a tuya or moberg, which is a volcano erupted under an icecap. The base layer is breccia formed by violent phreatic eruptions under the lake formed in the ice cap by the magmatic heat. The middle yellow layers are palagonite weathering of steeply dipping ash layers. The top caprock is composed of black layers are basalt flows that erupted after the meltwater lake drained away, resulting in subaerial lava flows.[5]

References

  1. ^ a b c Public Domain This article incorporates public domain material from "Brown Bluff". Geographic Names Information System. United States Geological Survey.
  2. ^ Elias, Scott A.; Mock, Cary J. (2013). Encyclopedia of Quaternary Science. Elsevier.
  3. S2CID 128894569
    .
  4. ^ "Brown Bluff". BirdLife data zone: Important Bird Areas. BirdLife International. 2012. Archived from the original on 2007-07-10. Retrieved 2012-12-10.
  5. ^ Joseph Holliday, Earth Science Department, El Camino College

External links