TV talk show queen Oprah Winfrey is at the centre of a controversy over the tsunami warnings triggered by this week’s mammoth earthquake in far eastern Russia.

As warning sirens sounded on Wednesday amid threats of a tsunami trigged by the magnitude 8.8 tremor off Russia’s far eastern Kamchatka coast, there was panic across the islands of Hawaii as people rushed for higher ground.

Rumours began to spread that Hawaiian locals fleeing expected tidal surges could not use a private, gated road on Winfrey’s $154 million estate on the island of Maui. Instead, according to the online chatter, they were forced to use the only other route, which added several hours to the journey.

Winfrey is one of a host of stars and high-profile figures who own property on Maui. Others include Woody Harrelson, Jeff Bezos, Owen Wilson and Mark Zuckerberg.

Her luxury estate has a private road that connects the coastal area of Wailea to the uplands of Kula via an inland route.

The road was eventually opened to the public, with anger intensifying as the online rumour mill insisted it was only due to the backlash. Later on Wednesday (local time), a Winfrey rep issued a statement.

“As soon as we heard the tsunami warnings, we contacted local law enforcement and [the US Federal Emergency Management Agency] to ensure the road was opened,” they told People magazine.

“Any other reports are otherwise false. Local law enforcement are currently on site helping residents through 50 cars at a time to ensure everyone’s safety. The road will remain open as long as necessary.”

The first waves reached Hawaii around 7.30pm local time (3.30pm Australian time). They peaked at about two metres, short of what authorities had forecast.

Warnings for the US island state have since been downgraded.

Hawaii was among many territories that issued tsunami alerts following Wednesday’s quake, which Russian scientists said was the biggest in the Kamchatka Peninsula region since 1952.

It was also the strongest earthquake anywhere in the world since since 2011, when a 9.0 magnitude tremor hit Japan’s eastern seaboard – and among the top 10 strongest detected worldwide

Warnings downgraded

Authorities in French Polynesia have also lifted a tsunami alert in the Marquesas Islands and said people can return to their homes, while urging caution.

Tsunami waves were smaller than initially feared, authorities said.

The French High Commission in French Polynesia said wave heights had reached 1.5 metres, down from a forecast of up to four metres. Further smaller waves were still expected, officials said.

The Marquesas Islands, among the most remote in the world, have a population of approximately 9500, according to a 2022 census.

Elsewhere in French Polynesia, wave heights were expected to remain below 30 centimetres, not requiring people to flee or shelter.

Some initial wave surges were reported on Nuku Hiva, the largest of the Marquesas, about 1400 kilometres north-east of Tahiti, the French high commission said.

In Severo-Kurilsk in Russia’s northern Kuril Islands, the largest tsunami waves reached five metres, Russia’s RIA news agency reported.

An aftershock of magnitude 6.07 later struck the Kuril Islands, which lie between Kamchatka and northern Japan, the German Research Centre for Geosciences said.

Tsunami waves partially flooded the port and a fish-processing plant in Severo-Kurilsk, sweeping vessels from moorings, regional officials and Russia’s emergency ministry said.

Verified drone footage showed the town’s shoreline submerged, with taller buildings and some storage facilities surrounded by water.

The Klyuchevskoy volcano on Russia’s Kamchatka Peninsula has since begun erupting, a geological monitoring service said.

About 450 kilometres north of the regional capital, Petropavlovsk-Kamchatsky, Klyuchevskoy is one of the highest volcanoes in the world.

“A descent of burning hot lava is observed on the western slope. Powerful glow above the volcano, explosions,” the Russian Academy of Sciences’ United Geophysical Service said on Telegram.

There were also waves of nearly half a metre in California, with smaller ones reaching Canada’s province of British Columbia. But a tsunami advisory was cancelled for coastal British Columbia and coastal areas of south Alaska.

Kamchatka and Russia’s far east sit on the Pacific Ring of Fire, a geologically active region that is prone to earthquakes and volcanic eruptions.

The quake occurred on what is known as a “megathrust fault” where the denser Pacific Plate is sliding underneath the lighter North American Plate, according to scientists.

The Pacific Plate has been on the move, making the Kamchatka Peninsula off Russia’s far east coast especially vulnerable, and bigger aftershocks could not be ruled out, they said.

Video footage from the region’s health ministry showed a team of medics in Petropavlovsk-Kamchatsky performing surgery as the quake shook their operating theatre.

The medics used their hands to try to steady both the patient and their equipment, CCTV footage released by the Kamchatka region’s health ministry showed.

-with AAP