Rabaul caldera | |
---|---|
Highest point | |
Elevation | 688 m (2,257 ft) [1] |
Listing | List of volcanoes in Papua New Guinea |
Coordinates | 4°16′16″S152°12′11″E / 4.27111°S 152.20306°E [1] |
Geography | |
Geology | |
Age of rock | ~1,400 years |
Mountain type | Pyroclastic shield/Caldera |
Volcanic arc/belt | Bismarck volcanic arc |
Last eruption | August to September 2014 [1] |
The Rabaul caldera, or Rabaul Volcano, is a large volcano on the tip of the Gazelle Peninsula in East New Britain, Papua New Guinea, and derives its name from the town of Rabaul inside the caldera. The caldera has many sub-vents, Tavurvur being the most well known for its devastating eruptions over Rabaul. The outer flanks of the highest peak, a 688-metre-high asymmetrical pyroclastic shield, are formed by thick pyroclastic flow deposits. [1] There is no sign of a pyroclastic shield along the rim of the caldera, making the location likely underwater, on the caldera's floor.
Tavurvur, a stratovolcano and a sub-vent of the caldera, is the most visibly active, continuously throwing ash. In 1994 it, and nearby Vulcan, erupted and devastated Rabaul; however, due to planning for such a catastrophe, the townsfolk were prepared and only five people were killed. One of the deaths was caused by lightning, a feature of volcanic ash clouds. [2] [3] [4]
In 1937, Vulcan and Tavurvur erupted simultaneously, killing 507 people. This event led to the founding of the Rabaul Volcano Observatory, which watches over the many active volcanoes in Papua New Guinea. [5] One eruption over several days in March 2008 released a plume of ash and water vapor that drifted northwest over the Bismarck Sea. [6]
After this eruption, GPS data showed deflation of Tavurvur cone. Seismicity was very low, and diffuse white plumes were emitted during 26–30 July. [11]
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Rabaul is a township in the East New Britain province of Papua New Guinea, on the island of New Britain. It lies about 600 kilometres to the east of the island of New Guinea. Rabaul was the provincial capital and most important settlement in the province until it was destroyed in 1994 by falling ash from a volcanic eruption in its harbour. During the eruption, ash was sent thousands of metres into the air, and the subsequent rain of ash caused 80% of the buildings in Rabaul to collapse. After the eruption the capital was moved to Kokopo, about 20 kilometres (12 mi) away. Rabaul is continually threatened by volcanic activity, because it is on the edge of the Rabaul caldera, a flooded caldera of a large pyroclastic shield.
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