How tsunamis work - Alex Gendler. If you live near the coast, it couldn't hurt to know what to do in case of a tsunami.
Do not wait for an official warning. Instead, let the strong shaking in the earth be your warning. After protecting yourself from falling objects, quickly move away from the water and to higher ground. Tsunamis are one of the most catastrophic natural disasters possible. What causes a tsunami? Earthquake tsunamis begin when subduction occurs, a process where larger undersea plates slide under a lighter plate.
In certain cases, the lighter plate shifts upward suddenly, stemming from the pressure of the other plate. This sends shoots of rocks upward, transferring powerful energy through the water and above sea level. The gravity forces the energy out in a horizontal fashion and along the surface, the equivalent of a ripple effect that is seen when an object is thrown into the water. The energy spreads away from the disturbance area. The energy transfer formulates the tsunami, but the size depends on the water levels, since tsunamis travel faster in deeper waters. What causes Tsunamis? Tsunami are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean.
Earthquakes Most tsunami are caused by large earthquakes on the sea floor when slabs of rock move past each other suddenly, causing the overlying water to move. Tsunami. Tsunami warnings Before a tsunami During a tsunami After a tsunami.
EQC Earthquake Commission. A tsunami is a series of powerful ocean surges that is caused by a large volume of the ocean being displaced – often by an undersea earthquake.
Most tsunamis resemble very strong, fast tides, rather than waves. These can penetrate a long way inland. Much of the damage from tsunamis is caused by the strong currents and floating debris. All of New Zealand's coastline is at risk from tsunamis. Tsunami Safety Tips, Tsunami Preparation, Tsunami Readiness. Occurrence and history of the most destructive seaquakes. Tsunamis are disasters that threaten coasts and beaches all over the world.
From observations of scientists and historical sources, we know today that tsunamis are a global phenomenon, they are possible in all of the world’s oceans and seas, including the Mediterranean, the Atlantic, the Indian, the Pacific, and even in large lakes where they can be caused by landslides. Frequency and pattern of tsunami generation appears to be linked to the cycle of each region of the world and the pattern and range of small to large destructive tsunami events. Tsunamis can only occur in coastal regions and islands are the main targets. However, even if mostly beaches and coastlines are affected by tsunamis, the wave front can advance in estuaries many miles inland. Image: A tsunami historical outlook around the globe. Tsunami / Natural Hazards / Our Science / Home - GNS Science.
GNS Science works with a number of groups, including NIWA, universities, and private individuals, to improve the knowledge of tsunami hazards in New Zealand.
Understanding Tsunami Identify tsunami sources, and modelling tsunami generation, propagation and inundation Studying offshore faults and earthquakes that may produce local tsunami. Identifying tsunamis that have occurred over the past few thousand years around the New Zealand coastline. Searching out data on the sources and the damage and wave heights of historical tsunami (the past 200 years). Tsunami in New Zealand / Tsunami / Natural Hazards / Our Science / Home - GNS Science. Has New Zealand been hit by tsunamis? New Zealand has experienced about 10 tsunamis higher than 5m since 1840. Some were caused by distant earthquakes, but most by seafloor quakes not far off the coast. Tsunami wreaks havoc on Southeast Asia - Dec 26, 2004. On the day after Christmas in 2004, a massive undersea earthquake occurs just off the coast of Indonesia at a few minutes before 8 a.m. local time.
With a magnitude of 9.3, the quake was the most powerful of the last 40 years and the second largest earthquake in recorded history. It set off a deadly tsunami that, in the final estimate, killed an estimated 230,000 people and wreaked untold devastation on a wide swath of coastline from Somalia on the east African coast to Sumatra in Southeast Asia. The Deadliest Tsunami in History? Updated January 7, 2005 Tsunamis: Facts About Killer Waves The earthquake that generated the great Indian Ocean tsunami of 2004 is estimated to have released the energy of 23,000 Hiroshima-type atomic bombs, according to the U.S.
Geological Survey (USGS). Review of Tsunami Hazard in New Zealand » Ministry of Civil Defence and Emergency Management. New tsunami report a sound basis for mitigation measures Recent tsunami research has presented New Zealand with a mixed bag of news.
Parts of our coast are exposed to greater tsunami hazard than previously thought, while the hazard in other coastal regions is the same or less. The findings come from a new GNS Science report commissioned by the Ministry for Civil Defence and Emergency Management. It updates a report on New Zealand’s tsunami hazards that we compiled in 2005. – Tsunamis. Tsunamis have been a danger in New Zealand as long as people have lived there. Archaeological studies have shown that during the mid-15th century, many Māori moved their settlements from low-lying coastal sites to hilltops and inland sites.
A number of the abandoned coastal settlements show clear evidence of tsunami inundation. Tsunamis are also recorded in Māori oral tradition. Gisborne tsunami, 25 March and 17 May 1947 - Tsunami.