Heard Island Volcano - John Seach

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(Big Ben, Mawson Peak)

Australian Territory, South Indian Ocean

53.106 S, 73.513 E
summit elevation 2745 m
stratovolcano

Heard Island is located 4000 kilometres southwest of Western Australia and contains one of Australia's two currently active volcanoes. Volcanic activity has been reported at the island since the 1881.

Heard Island covers an area of 368 sq km. Mawson Peak at 2745 m is the highest mountain on Australian territory, outside Australian Antarctic Territory.

Heard Island is located in the `Furious Fifties’ , where strong winds blow mainly from the west. A mean sea-level wind speed of 26 km/h and a maximum gust of 209 km/h were recorded between December 1947 and March 1955, when an Australian base
was maintained at Atlas Cove on the western side of Big Ben.

Heard Island sits on the submarine Kerguelen Plateau, which rises 3700 m above
the sea floor, and deflects Antarctic circumpolar bottom water northward past Kerguelen Islands.

The McDonald Island group lies 43.5 km west of Heard Island, and consists of McDonald Island (area 1 sq km), and the much smaller Flat Island and Meyer Rock.

Heard Island Weather
An Australian base was maintained at Atlas Cove on the western side of Big Ben between December 1947 and March 1955, where weather observations were recorded. The mean annual air temperature recorded at Atlas Cove is 1 deg C. Maximum recorded temperatures are 14°C at Atlas Cove, and the lowest temperature recorded is -9°C. Average annual precipitation recorded at Atlas Cove is 1350 mm, with precipitation occurring on 300 days per year, and being highest in late summer and early autumn. Snow falls to sea level throughout the year. Mean sunshine hours vary from 2.4 hours per day in November to 0.8 hours per day in June.

Big Ben is the name of the main active volcano and the summit peak is called Mawson Peak. The 20 km wide volcano is located in the centre of the island and radiating outwards are 14 glaciers.

Mount Dixon (706 m) volcano lies at the NW tip of the island across a narrow isthmus.

Laurens Peninsula is a subsidiary volcanic centre from which basaltic to trachytic
lava was emitted. Mt Olsen (636 m) and Anzac Peak (715 m) are two eroded volcanoes on the peninsula.

Heard Island Glaciers
Downes, Ealey, Compton, Brown, Stephenson, Winston, Fiftyone, Deacock, Gotley, Lied, Abbotsmith, Allison, Schmidt, Baudissin.

History
Heard Island was discovered by Captain John Heard in 1853. The remoteness of the island and harshness of climate has meant that few expeditions have reached the area. The Australian Antarctic Division mounted a research expedition to the Heard Island over the summer of 2003-2004. The team undertook a 10-week research programme that focused on studies of glaciology, terrestrial ecology and predator/prey relationships.

2014 Eruptions
Satellite images showed a hotspot over the volcano on 1st January 2014, indicating continuing eruptions. Renewed activity indicated by hotspot visible on satellite image on 16th November 2014.

2013 Eruptions
Pilot reports ash emissions at Heard Island volcano, southern Indian Ocean. Satellite image shows hotspot at summit on 1st October 2013.

2012 Eruptions
Satellite images showed hotspots at Heard Island volcano on 21 and 24 September, 28th October, 6th November, and 11th December 2012. This indicates renewed activity at the volcano. Heard Island is located 4000 kilometres southwest of Western Australia and contains one of Australia’s two currently active volcanoes. Volcanic activity has been reported at the island since the 1980's. The eruptions were first detected and reported by John Seach while searching for volcanic activity on satellite images.
A Heritage Expeditions cruise which departed Fremantle, Australia, reached Heard Island in the south Indian Ocean on 21st November 2012. A photo posted on the expedition's twitter page showed the volcano under clear skies. There was no visible plume from the summit. This expedition was the first to reach Heard Island in the current cycle of volcanic activity.

2008 Eruptions
Satellite images showed hotspots at Big Ben volcano, Heard Island in February and March 2008.

2007 Eruptions
Satellite hotspots indicated Big Ben volcano was active throughout most of 2007. Two hotspots separated by 300 m were detected on 29th February 2007, and possibly indicated separate active vents at the volcano.

2006 Eruptions
Satellite hotspots indicated eruptive activity at Big Ben volcano throughout most of 2006. There was evidence that a lava lake was present in the summit crater, however this cannot be confirmed by satellite images alone.

2003-04 Eruptions
Satellite hotspots began to be detected on 9th June 2003, and continued frequently until 14th June 2004.

2001 Eruptions
On 2nd February 2001, observations from Atlas Cove, 15 km NW of the summit, showed plumes up to 1 km high over the volcano. The eruptions appeared to originate from two vents, one at Mawson Peak, and the other at a newly discovered vent 300-400 m further down the south flank.

2000 Eruptions
Satellite images detected eruptions at Big Ben volcano, Heard Island on 24 May; 3, 5, and 6 June; 25 September; 29 October; 5, 15, 19, and 24 November; 16, 17, 26, and 30 December 2000.

1993 Eruption
A new lava flow was observed at Mawson Peak, Heard island in mid January 1993. Lava flowed in two lobes from 2600 m altitude to below 1400 m altitude, on the SW flank of the volcano. Lava followed the same path taken by the 1985-87 lava flow.

1992 Eruption
On 29th May 1992, an orange glow was observed above the volcano. Pulsating cycles of incandescence occurred between 2130 and 2200 hr.

1986-87 Eruption
A helicopter landing was made at the summit of Mawson Peak by Australian National Antarctic Research Expeditions (ANARE) on 21st December 1986. Incandescent lava was visible inside the 40-50 m wide, 50-70 m deep crater. The crater appears to have been formed by the 1985-87 eruption because it was not seen by climbing expeditions which reached the summit of Mawson Peak in 1965 and 1983.

1985 Eruption
On 14-15 January 1985 a lava flow was observed erupting from a vent at 2,750 m altitude, on the upper south flank of Big Ben volcano, Heard Island. The lava flow extended 7 km towards Cape Arkona.

Heard Island Volcano Eruptions

2014, 2013, 2012, 2006-08, 2003-04, 2000-01, 1993, 1992, 1985-87, 1954, 1953, 1950-52, 1910, 1881