Tsunami warning: What to do if you are caught in an area threatened by severe coastal waves

Advice on staying safe as US Pacific coast on high alert following earthquake

The US west coast is on high alert for a tsunami after a 7.9-magnitude earthquake struck 160 miles off the coast of Alaska.

The shallow depth of the seismic shock's epicentre, just 6.2 miles below the surface, prompted the US Tsunami Warning System to issue a red warning for Alaska and western Canada.

The rest of the US Pacific coast was placed on tsunami watch, indicating the need for vigilance against strong ocean waves but a lower level of immediate concern.

:: Follow the latest updates following the tsunami warnings

But what should you do if you are in one of the areas affected by the wave threat?

The official advice from the Tsunami Warning Centre on protecting human life and property is as follows:

• Evacuate inland or to higher ground above and beyond designated tsunami hazard zones or move to an upper floor of a multi-storey building, depending on your situation.
• Move out of the water, off the beach and away from harbours, marinas, breakwaters, bays and inlets.
• Be alert to and follow instructions from your local emergency officials because they may have more detailed or specific information for your location.
• If you feel a strong earthquake or extended ground rolling, take immediate protective actions such as moving inland and/or uphill, preferably on foot.

Boat operators are instructed, where time and personal safety allow, to move their vessels out to sea to a depth of at least 180 feet.

Those already at sea should avoid entering shallow water, harbours, marinas, bays and inlets to avoid the risk of being hit by floating or submerged debris and strong currents.

More general advice offered by the Tsunami Centre includes staying away from coastal areas to observe the waves - the Red Cross advises that if you can see it, you are too close - and not returning until advised that it is safe to do so by local emergency officials. They stress the need to save yourself, not your possessions.

Emergency supplies and safety clothing organised in advanced are recommended and those evacuating are also advised to check on the welfare of their neighbours and come to the aid of infants, the elderly and those with large families or who might otherwise require assistance.

If further help is needed, call the emergency services and do not place yourself in danger by remaining in the disaster zone - your presence could hinder the operations of response units.

Those in a tsunami watch area should prepare to take action and stay alert to local media for further information.