White Island Eruption Summary. 30 December 2019
The three periods featured several significant quakes, including an important eruption precursor, the 24 November White Island 5.9. Multiple eruptions occurred during the period. Sadly the 9 December ash eruption blew away the lives of 19 people trapped inside the crater and left 28 more seriously burnt. Prior to the fateful eruption, tremor had been building steadily since the 24 November Mag 5.9. Frustratingly for the forecasters, Geonet gave a different location (about 10km NE of White Island) to United States Geological Survey USGS and European Mediterranean Seismological Centre EMSC (about 10km SE of White Island) for the moderately deep 115km Mag 5.9. Increasing volcanic tremor was confirmed by local tour guides who saw increasing steam activity at the vent over the next days. The 8 December 2200 eruption shows as a classic tremor spike and sudden dropoff on a standard Seismic Spectral Amplitude Measurement graph. The night eruption was probably phreatic (steam) because next day the tour guides didn't notice any ash. Following the sudden fateful ash eruption, the volcano went into a period of low frequency tremor and constant steam emissions. SAS soldiers nearly cooked themselves in a dangerous operation to recover the bodies from the crater, reporting extreme temperatures. The volcano then went quiet as spaceweather faded away and the forecast period ended. Two more tremor increases show on the SSAM graph 18-20 December and 25-26 December, corresponding with spaceweather/forecast periods, Kermadec and Vanuatu quakes occuring at the peaks. The last time White Island erupted significantly on 5 August 2012, the day before the 6 August 2012 Tongariro eruption and three weeks after undersea Kermadecs volcano Havre. Eruption and quake clustering is common in time and location, matching clustered solar activity. The 5 August 2012 White Island eruption was followed soon after by the January-March 2013 White Island eruption sequence and early forecast success, leading to big Cook Strait quakes in 2013. Returning to 2019, weakest solar activity in a century has kept Pacific volcanos and quakes subdued as Solar Cycle 24 ends and Solar Cycle 25 begins. Isolated but possibly strong bursts of solar activity could drive a new round of Pacific and New Zealand quakes March-April-May as Solar Cycle 25 picks up in 2020. Time will tell. SSAM graph courtesy Geonet. Quake data courtesy USGS, EMSC, Geonet. Solar data courtesy NASA. Aotearoa Earthquake and Volcano Forecast Service © 2013 - 2024 |
