Tsunami

A tsunami (from Japanese: 津波, "harbour wave"; English pronunciation: /tsuːˈnɑːmi/ ) or tidal wave, also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Unlike normal ocean waves which are generated by wind, or tides which are generated by the gravitational pull of the Moon and Sun, a tsunami is generated by the displacement of water.

Tsunami waves do not resemble normal undersea currents or sea waves, because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide, and for this reason they are often referred to as tidal waves, although this usage is not favoured by the scientific community because tsunamis are not tidal in nature. Tsunamis generally consist of a series of waves with periods ranging from minutes to hours, arriving in a so-called "internal wave train". Wave heights of tens of metres can be generated by large events. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous and they can affect entire ocean basins; the 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean.

Greek historian Thucydides suggested in his late-5th century BC History of the Peloponnesian War, that tsunamis were related to submarine earthquakes, but the understanding of a tsunami's nature remained slim until the 20th century and much remains unknown. Major areas of current research include trying to determine why some large earthquakes do not generate tsunamis while other smaller ones do; trying to accurately forecast the passage of tsunamis across the oceans; and also to forecast how tsunami waves interact with specific shorelines.

Tsunami Safety Rules

Not all earthquakes cause tsunamis but many do. When you feel that an earthquake has occurred, stand by for a tsunami emergency message.
A tsunami is not a single wave but a series of waves. Stay out of danger areas until an "all-clear" is issued by a competent authority.
Approaching tsunamis are sometimes preceded by a noticeable rise or fall of coastal water. This is nature's tsunami warning and should be heeded.
A small tsunami at one point on the shore can be few miles away. Don't let the modest size of one make you lose respect for all.
All warnings to the public must be taken very seriously, even if some are for non-destructive events. The tsunami of May, 1960 killed 61 people in Hilo, Hawaii because some thought it was just another false alarm.
All tsunamis are potentially dangerous though they may not damage every coastline they strike.
Never go down to the shore to watch for a tsunami. When you can see the wave you are too close to escape it. Never try to surf a tsunami; most tsunamis are like a flash flood full of debris and they do not curl or break like surfing waves.
Please give your fullest cooperation to local authorities, police and other emergency organizations that try to save your life.

BEFORE A TSUNAMI:

Learn the buzzwords – Learn words used by both the West Coast / Alaska Tsunami Warning Center (WC/ATWC – for AK, BC, CA, OR, and WA) and the Pacific Tsunami Warning Center (PTWC – for international authorities, HI and all U.S. territories within Pacific basin) for tsunami threats…

Advisory – an earthquake has occurred in the Pacific basin which might generate a tsunami
Watch – a tsunami was or may have been generated, but is at least 2 hours travel time from Watch area
Warning – a tsunami was / may have been generated and could cause damage to Warning area – should evacuate

Learn risks – If new to area, call local emergency management office and ask what the warning signals are and what to do when you hear them. Coastal areas less than 25 feet above sea level and within a mile of shoreline along coasts are at greatest risk. Or visit www.tsunamiready.noaa.gov

Make a plan – Develop a Family Emergency Plan (e.g. establish meeting places, list of emergency contact #s, out of state contact person, etc) and Disaster Supplies Kits.

Listen – Make sure you have a battery-operated radio (with spare batteries) for weather forecasts and updates. (Radios like Environment Canada’s Weatheradio and NOAA’s Weather Radio have a tone-alert feature that automatically alerts you when a Watch or Warning has been issued.)

Water signs – If near water or shore, watch for a noticeable rise or fall in the normal depth of coastal water – that’s advance warning of a tsunami so get to high ground. Also – if water pulls away from shoreline and exposes sea floor – run to higher ground ASAP!!

Feeling shaky…? – If you feel an earthquake in the Pacific Coast area (from Alaska down to Baja), listen to the radio for tsunami warnings.

Is that it…? – Don’t be fooled by the size of one wave – more will follow and they could get bigger … and a small tsunami at one beach can be a giant wave a few miles away!

Be ready to evacuate – Listen to local authorities and leave if you are told to evacuate.

DURING A TSUNAMI:

Leave – If you are told to evacuate, DO IT! Remember – a tsunami is a series of waves – the first one may be small but who knows what the rest will bring. Grab your BOB/Disaster Supplies Kit and GO!

IF ON OR NEAR SHORE – Get off the shore and get to higher ground quickly! Stay away from rivers and streams that lead to the ocean since tsunamis can travel up them too. You cannot outrun a tsunami … if you see the wave it’s too late!

IF ON A BOAT – It depends where you are — either get to land or go further out to sea …

In port – May not have time to get out of port or harbor and out to sea – check with authorities to see what you should do. Smaller boats may want to dock and get passengers and crew to land quickly.

In open ocean – DO NOT return to port if a tsunami warning has been issued since wave action is barely noticeable in the open ocean! Stay out in open sea or ocean until authorities advise danger has passed.

Don’t go there – Do NOT try to go down to the shoreline to watch and don’t be fooled by size of one wave – more will follow and they could get bigger so continue listening to radio and TV.

AFTER A TSUNAMI:

Listen – Whether on land or at sea, local authorities will advise when it is safe to return to the area — keep listening to radio and TV updates.

Watch out – Look for downed power lines, flooded areas and other damage caused by the waves.

Don’t go in there – Try to stay out of buildings or homes that are damaged until it is safe to enter and wear sturdy work boots and gloves when working in the rubble.

Strange critters – Be aware that the waves may bring in many critters from the ocean (marine life) so watch out for pinchers and stingers!

RED or GREEN sign in window – After a disaster, Volunteers and Emergency Service personnel may go door-to-door to check on people. By placing a sign in your window that faces the street near the door, you can let them know if you need them to STOP HERE or MOVE ON. Either use a piece of RED or GREEN construction paper or draw a big RED or GREEN “X” (using a crayon or marker) on a piece of paper and tape it in the window.

RED means STOP HERE!
GREEN means EVERYTHING IS OKAY…MOVE ON!
Nothing in the window would also mean STOP HERE!

Insurance – If your home suffers any damage, contact your insurance agent and keep all receipts for clean-up and repairs.

Mold – Consider asking a restoration professional to inspect your house for mold. Also check out www.epa.gov/mold

Some additional things to check and do…

Check electrical system (watch for sparks, broken wires or the smell of hot insulation)

Check appliances after turning off electricity at main fuse and, if wet, unplug and let them dry out. Call a professional to check them before using.

Check water and sewage system and, if pipes are damaged, turn off main water valve.

Throw out food, makeup and medicines that may have been exposed to flood waters and check refrigerated foods to see if they are spoiled. If frozen foods have ice crystals in them then okay to refreeze.

Throw out moldy items that are porous (like rotten wood, carpet padding, furniture, etc.) if they’re too difficult to clean and remove mold. Remove standing water and scrub moldy surfaces with non-ammonia soap or detergent, or a commercial cleaner, rinse with clean water and dry completely. Then use a mixture of 1 part bleach to 10 parts clean water to wipe down surfaces or items, rinse and dry.

Secure valuable items or move them to another location, if possible

Here are some videos from Youtube that show you how it looks like.

Credit to the owner of the video