Waves of lava are threatening countless properties, roads and forests on Hawaii’s Big Island as the Kilauea volcano continues erupting. The lava is spraying up in fountains up to 70 metres high, and reaching temperatures of more than 1000°C.

Already, , including 26 homes in and around the island’s Leilani Estates area in the Puna district. .

Kilauea is one of the most active volcanoes in the world. It became more active after 30 April when the floor of a lava lake at the volcano’s summit collapsed. Lava was sent cascading down into the volcano’s plumbing.

The collapse fuelled multiple earthquakes, including on 3 May, the island’s largest for 40 years.

By Monday 12 large fissures had opened up along the East Rift Zone, which runs from Kilauea’s summit down through the Puna district, . The cracks are spewing toxic sulphur dioxide gas and molten lava.

Flow of lava

“The most likely scenario is more fissures, and more lava flow,” says , a volcanologist at the University of East Anglia, UK, who spent two years at the studying Kilauea. “There’s still a lot of lava and pressure being supplied, but there’s unlikely to be an explosion.”

Kilauea’s biggest recorded eruption was , says Johnson. This happened when boiling magma under the volcano heated up large reserves of underground water. The steam generated created so much pressure that the volcano blew. But today there are many pathways by which the magma can reach the surface without hitting water, so a major eruption is less likely, says Johnson.

However, the slow-moving lava is wreaking plenty of havoc. “It’s devastating,” says Johnson. “The gas is very dangerous, and lava flow has already flowed a kilometre from one fissure, destroying properties.”

Slowly sinking

Hurricane Irma has pummelled Florida, packing winds up to 130mph, swamping homes and boats, knocking out power to millions and toppling massive construction cranes over the Miami skyline.

The 644-kilometre-wide storm blew ashore in the mostly cleared-out Florida Keys, then marched up its western coast, its punishing winds extending clear across to Miami and West Palm Beach on the Atlantic side.

Irma’s core was nearing the heavily-populated Tampa and St. Petersburg area early on Monday, moving inland in a much-weakened state. While it arrived in Florida a category four hurricane, by nightfall it was down to category two with winds of 160km/h.

Meanwhile, more than 160,000 people waited in shelters statewide as Irma headed up the coast.

Bryan Koon, Florida’s emergency management director, said authorities had only scattered information about the storm’s toll, but he remained hopeful. “I’ve not heard of catastrophic damage. It doesn’t mean it doesn’t exist. It means it hasn’t gotten to us yet,” he said.

Widespread damage

In the low-lying Keys, where a storm surge of over 3 metres was recorded, appliances and furniture were seen floating away and Monroe County spokeswoman Cammy Clark said the ocean waters were filled with navigation hazards, including sunken boats.

County administrator, Roman Gastesi said crews would begin house-to-house searches to check on survivors and an airborne relief mission led by C-130 military cargo planes is gearing up to bring emergency supplies to the Keys.

Storm surge was a big concern, with a federal tide gauge in Naples reporting a 2m rise in water levels in just 90 minutes late on Sunday. Many streets were flooded in central Miami and other cities.

An apparent tornado spun off by Irma destroyed six mobile homes in Palm Bay, midway up the Atlantic coast, and flooding was reported along Interstate 4, which cuts across Florida’s mid-section.

Curfews were imposed in Miami, Tampa, Fort Lauderdale and much of the rest of South Florida, and some arrests of violators were reported. Miami Beach barred outsiders from the island. Fort Lauderdale police arrested nine people they said were caught on TV cameras looting trainers and other items from a sports store and a pawn shop during the hurricane.

More than 3.3 million homes and businesses across the state lost power, and utility chiefs said it will take weeks to restore electricity to everyone.

Enormous storm

While Irma raked Florida’s Gulf Coast, forecasters warned that the entire state was in danger because of the sheer size of the storm – which has likely been fuelled, in part, by climate change. In one of the largest US evacuations, nearly seven million people in the south east were warned to seek shelter elsewhere, including 6.4 million in Florida alone. About 30,000 people heeded orders to leave the Keys as the storm closed in, but an untold number refused, in part because, to many storm-hardened residents, staying behind in the face of danger is a point of pride.

John Huston, who stayed in his Key Largo home, watched his garden flood even before the arrival of high tide. “Small boats floating down the street next to furniture and refrigerators. Very noisy,” he said. “Shingles are coming off.”

Irma made landfall just after 9am at Cudjoe Key, about 32km outside Key West. During the afternoon, it rounded Florida’s south-western corner and hugged the coast closely as it pushed toward Naples, Sanibel, Fort Myers and, beyond that, Sarasota, at 23km/h. Forecasters warned some places could see a storm surge of up to 4.5m of water.

Gretchen Blee, who moved with her husband to Naples from Long Island, New York, after Superstorm Sandy heavily damaged their beach home in 2012, took cover in a hotel room as Irma raged. “I said, ‘Let’s go and live the good life in paradise’,” she said. “And here we are.”

Irma comes just a couple of weeks after Hurricane Harvey struck Houston, Texas and the surrounding area, causing catastrophic flooding. Such events are likely to be more common as the climate continues to warm.

Dramatic drop