Growth and collapse of a littoral lava dome during the 2018/19 eruption of Kadovar Volcano, Papua New Guinea, analyzed by Multi-Sensor Satellite Imagery

Kurzfassung

Growing volcanic islands and lava domes become structurally unstable, associated with sectoral collapses, explosive volcanism and related hazards. This article describes the rare case of a growing and collapsing lava dome at Kadovar Volcano, a small inhabited volcanic island located north of Papua New Guinea. The eruption began on January 5, 2018 and was monitored by multi-sensor satellite imagery, including optical, thermal and synthetic aperture radar (SAR) sensors. Results show that Kadovar began a new episode of volcanic activity at the central crater and then also at the eastern coast of the island. SAR amplitude imagery has made it possible to monitor the birth of a new peninsula on the eastern coast. This new peninsula has a blocky appearance and is associated with a localized thermal anomaly, which is indicative of an emerging lava dome. We analyzed the changes on the island and the peripheral lava dome and found that after a great increase in the size of the area, parts of the island and the lava dome then collapsed eastwardly into the ocean on February 9, 2018. The sector collapse caused small tsunami waves that hit the neighboring islands. A subsequent slower re-growth of the lava dome is evident from the satellite data, which has reached a final area of ~40,000 m². This study provides details on the rapid growth and collapse of a peripheral lava dome and a destabilization episode in an island and dome sector, and underlines the great value of remote sensing data on remote volcanic islands.