Monovai submarine volcano (Kermandec Islands): eruptions occurred in October 2014

New Zealand scientists concluded that most likely 3 underwater eruptions occurred during this October at the shallow submarine volcano, one of the most active ones in the Tonga-Kermadec arc.
This conclusion was based on both the observation of a pumice raft in the area on 31 Oct and the analysis of so-called T-waves, a particular kind of acoustic waves that propagate well in the ocean and have been found to be typically associated with submarine eruptions from Monovai seamount.
These T-waves were recorded Rarotonga, Polynesia, more than 1800 km from the volcano. They show 3 periods of possible activity at Monovai: during 16-22 Oct, 23-27 Oct and 30 Oct - early Nov. The latter corresponds well with the observation of the pumice raft on 31 Oct by the NZ airforce.
The last confirmed eruption at the volcano occurred in 2012. Although it is far from inhabited areas on land, the volcano has the potential of explosive eruptions to produce significant ash plumes which could threaten regional air routes. Another hazard is the occurrence of underwater landslides, which have been documented to occur by recent bathymetric comparison studies. Larger landslides at the steep underwater flanks could in turn trigger tsunamis.