Towering waves on Hawaii's south shores crashed into homes and businesses, spilt across motorways and ruined weddings at the weekend.
The large waves — some more than six metres high — came from a combination of a strong south swell, particularly high tides and rising sea levels associated with climate change, the National Weather Service said.
A wedding on Saturday evening in Kailua-Kona was interrupted when a set of large waves swamped the event, sending tables and chairs crashing towards guests.
Sara Ackerman, an author who grew up in Hawaii and attended the wedding, filmed the waves as they barrelled ashore.
“It just was huge,” she said. ”I was filming it and then it just came over the wall and just completely annihilated all the tables and chairs.”
She said it happened about five minutes before the ceremony was scheduled to begin.
“It wasn’t like a life-threatening situation by any means whatsoever,” she said. “It was just like, ‘Oh my gosh ... what are we going to do? Where are we going to put the tables?’”
She said they went ahead with the ceremony and cleaned up the mess after the newly-weds exchanged vows.
“We had the ceremony and it was beautiful, having all the [sea)] spray,” she said. “The ocean was really wild. So it was great for the photos.”
Chris Brenchley, the meteorologist in charge at the National Weather Service office in Honolulu, said several factors came together to create such huge waves.
“Waves over 12 or 15 feet [3.66 or 4.57 metres], those become extremely big and really rare to have," he said. “It’s the largest it’s been in several decades.”
Mr Brenchley said the swell was produced in the South Pacific, where it is currently the winter.
While isolated events such as this are hard to pin directly to climate change, Mr Brenchley said the warming planet is playing a role.
“The most direct type of impact that we can use with climate change is the sea level rise. Any time you add just even small amounts of water, you raise that sea level just a little bit,” he said.
“We had some waves that were reaching 20 feet (6 metres), 20 feet-plus even. That’s getting on the level of historic.”
Hawaii’s northern shores, where professional surfers often compete, usually get much larger waves than other parts of the islands. The predominant swell hits the north in the winter and the southern shores in summer.