3/22/2023 0 Comments Neptunes islandThe island was first charted in 1828-29 by Henry Foster of the HMS Chanticleer. The caldera was frequently used from 1821-1825, when the South Shetland Islands Fur Seal population was exploited to the verge of extinction. Since even large ships can enter the caldera through Nepune's Bellows, it has long provided protection from the often stormy waters of the subantarctic / antarctic region. Flank of Neptune's Bellows viewed from Whaler's Bay Southeast Point - Outer Flank of Deception Eruptions from these fissures destroyed the Chilean base and resulted in lahars which damaged the British base in Whaler's Bay. The 1967-1970 activity involved a number of vents near the N shore of the caldera and two fissures above Pendulum Cove and on Mount Pond. ![]() Historical eruptions have been reported in 1842, 1967, 19, although at least further eruptions must have occurred between 18 since several new volcanic features formed during this period but activity was not observed. Stitched Penorama: View over Whalers Bay (center), with Neptune's Bellows to left and Mt. The perimeter of the caldera is defined by a circular fault zone which has recently been the site of renewed volcanic activity. The simplest model is the collapse of a large pre-caldera stratovolcano following emptying of the magma chamber during a massive pre-historic eruption. ![]() Several models have been proposed for caldera formation (see e.g. ![]() The current maximum depth of the caldera is less than 200m as a result post-caldera sedimentary processes. The Island has an approximate diameter of 14km, with the water-filled caldera known as Port Foster extending for up to 8 x 10 km. Following formation of the caldera, numerous smaller eruptive events have modified the landscape at a variety of different sites. Horseshoe-shaped Deception Island is a massive caldera that resulted from the collapse of a large stratovolcano, followed by flooding of the resulting crater through a breach in the caldera walls at Neptune's Bellows.
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