An underwater volcano has erupted in the Pacific island nation of Tonga. Tsunami threats have now been issued in New Zealand and some parts of the United States. There is a Tsunami alert for the US west coast and flooding in Hawaii after this eruption. The eruption has led to heavy rainfall, thunder and lightning in the island. Meanwhile fumes of smoke have blackened the skies sending powerful waves through the region. The eruption was so intense that Fiji which is more than 800 kms from Tonga also heard loud thunder sounds.