Iceland’s president says the country is battling “tremendous forces of nature” after molten lava from a volcano consumed several houses in the evacuated town of Grindavik. President Gudni Th. Johannesson said in a televised address late Sunday that “a daunting period of upheaval has begun" on the Reykjanes peninsula in the southwest. A volcano on the peninsula erupted for the second time in less than a month on Sunday morning. Authorities had ordered residents to leave the fishing town of Grindavik hours earlier. Geophysicist Magnus Tumi Gudmundsson said on Monday that the eruption had “decreased considerably” overnight. But he said it was impossible to say when it would end.