AUSTRAL, February 28th, 2017, Ambrym Island, VanuatuPosted on Tuesday 7 March 2017
By Harry CHRISTENSEN
Ambrym Island, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides arc. A thick, almost exclusively pyroclastic sequence, initially dacitic, then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major plinian eruption with dacitic pyroclastic flows about 1900 years ago. Post-caldera eruptions, primarily from Marum & Benbow cones, have partially filled the caldera floor & produced lava flows that ponded on the caldera floor or overflowed through gaps in the caldera rim.
Post-caldera eruptions have also formed a series of scoria cones & maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations.
This was indeed, an auspicious event as this is the first time L´Austral has ever visited Ambrym Island. Our approach this morning was full of excitement as we glimpsed the imposing volcanic peaks rising to the dizzy heights of 1,334 m. We had a short Zodiac® trip to the volcanic black sand beach adjacent to the village of Ranon, where we were greeted with Expedition Leader José.
We all gathered under the shade of trees to witness a truly amazing authentic Ambrym performance. Here ancient custom play a significant part in day to day living, where “black magic” is common in beliefs. We witnessed a unique ‘kastom’ dance called the Rom (or masked) dance – where 3 m covertly covered cloaked & masked “spirit” stomp out ancient rhythms to the beat of the tam-tams. These are sculptured slit gongs carved from tree trunks, creating an ancient musical instrument.
We were mesmerised by this spectacular dance performance. Soon after, we witnessed another form of artistic expression through “sand drawing”.
Shortly afterward, we walked to the local Ranon village school.It was with sad hearts that we had to say our farewells to the friendly villagers of Ranon & return back to L´Austral, full of fond memories.