2009 Tonga Undersea Volcanic Eruption - Eruption History

Eruption History

The initial March 16–17 eruption sent ash and smoke up to 20 kilometres (12 mi) into the atmosphere and an initial inspection reported that the volcano has breached the ocean surface. Authorities suggested at that time that the eruption did not yet pose any threat to the capital's population, and an inspection team was sent out to evaluate the volcano.

Between March 18–20, a number of Surtseyan eruptions sent ash plumes as high as 4 kilometres (2.5 mi) to 5.2 kilometres (3.2 mi) into the atmosphere, with prevailing winds pushing the ash cloud about 480 kilometres (300 mi) east-northeast of the eruption site and widespread and significant haze reported at Vavaʻu 255 kilometres (158 mi) away. Steam plumes on March 20 were measured at 1.8 kilometres (1.1 mi) above sea level. But on March 21, an eruption sent steam and ash just 0.8 kilometres (0.50 mi) into the sky. On March 21, Tonga's chief geologist Kelepi Mafi reported lava and ash from two vents, one on the uninhabited island Hunga Haʻapai and another about 100 m (330 ft) offshore, had filled the gap between the two vents, creating new land surface that measured hundreds of square metres. The eruption devastated Hunga Haʻapai, covering it in black ash and stripping it of vegetation and fauna. Latest news: 30-SEP-2009 17:47:17 -15.45 -173.38 5.2 10.0 TONGA ISLANDS Magnitude 5.2 - TONGA