An underwater volcanic eruption in the Pacific has triggered Tsunami warnings. The hardest hit is the island of Tonga and NPR reported that communications with the island had been cut off.
The first major volcanic eruption struck today in the island nation of Tonga. Over the past few weeks, the small volcanic island of Hunga Tonga-Hunga Ha’apai had been experiencing minor but impressive explosions. However, on January 14-15, the eruption became much more violent, sending ash over 60,000 feet (18 kilometers) into the skies. The blast also generated a tsunami that hit many of the islands in Tonga, destroying homes and buildings across the country.
The blast was caught in spectular fashion by Japan’s Himawari-8 satellite. In this animated GIF (above), you can see the large explosion begin and the shockwave from the blast pass through the atmosphere away from the volcano for hundreds of miles like ripples in a lake. The shockwave was recorded in air pressure as far away as Anchorage having travelled over 5,800 miles (9,200 kilometers) and Florida. You can also see the thin, fast moving surge at the front of the growing cloud. This appears to be possibly the largest eruption in historic record for the volcano.
GOES-17, a NOAA weather satellite, caught the eruption plume forming as well (below). You can clearly see the initial upward thrust followed by the spreading of the cloud laterally as it hit neutral buoyancy in the atmosphere. The eruption also generated a large amount of volcanic lightning.
You can see the explosion in this news clip.
Tsunami warnings were triggered all along the west of the US. The waves hitting Tonga were in the 4 ft range but those reaching the US were in the 1-2 foot range, which does not sound like much, but can be dangerous to people on the shore, mainly because it can knock people over and when tsunami waves recede they can drag people back with it into the ocean.