Natural Disasters 2Earthquake & are among nature’s most terrifying forces. There will be one today. Tsunami Definitely. And it could strike in our region.

Introduction A power unleashed, all too frequently

ore than 80 per cent of quakes happen along the Pacific Ocean rim, also called the Pacific Ring of Fire because of Mthe many volcanoes also found here. Today’s could be so small that no one will feel it. But it may be one of the estimated 700 quakes a year big enough to cause death and damage. If it occurs at sea, it may trigger a tsunami. Large earthquakes have more than played their part in global natural hazards that in 2010* forced more than 42 million people to flee their homes. A large insurance company that tracks natural disasters says the 10 worst catastrophes of the past 30 years killed 1,089,570 people. Of this number, 654,570 died in earthquakes and tsunamis. Recent years have seen major disasters in Haiti, New Zealand, Chile, China and Japan. The deadliest occurred in poor, unprepared Haiti, where estimates of the death toll varied from 222,570 to more than 310,000. But it was the graphic television pictures of an exploding nuclear power plant and massive tsunami swells swallowing Japanese towns in March 2011 that sharpened our understanding of what destruction nature can unleash. Australia has quakes regularly, and large ones about once every five years, but they are often in remote and sparsely populated areas. An exception was Newcastle in 1989 when an earthquake killed 13 and cost the community $4.5 billion. The damage done by an earthquake depends on where it strikes. Australia, for example, had a big quake in remote Tennant Creek in 1988. It caused damage of about $2.5 million. It was larger than a 1994 earthquake near Los Angeles, . This one struck a built-up area, killed 60 people, injured 7000, left 20,000 homeless and caused $15 billion in damage. Collapsing buildings claim most lives, but people are killed, too, in mud and rock slides, fires and, of course, through the shocking power of tsunamis that sweep away everything in their paths. What causes earthquakes? Can we predict when they will happen? Why do some trigger tsunamis and others not? How do you measure their strength? Why does a massive quake in Chile kill a fraction of the numbers of a less powerful quake in Haiti? Nature does not always offer definitive answers to these kinds of questions. *Latest compiled figures Can earthquakes and tsunamis be predicted?

ot yet. Professor James Goff, of the Australian Tsunami Research Centre, says that you can say where they will most likely occur, but Nnot when. There will, for example, certainly be a big earthquake at a point off Indonesia within “tens” of years, he says. “That might be one year or 15 years, we can’t tell.” What’s more, not all underwater earthquakes generate tsunamis, even the big quakes. “It has to be the right movement of plates,” Professor Goff says. “Tsunamis occur when sea water is displaced, and for this to happen, the sudden movement of the tectonic plates have to either lift up or drop down. If the plates slip past each other sideways, you don’t get a tsunami.” Scientists can calculate the probability of big earthquakes in particular places. Professor John McCloskey, a research geophysicist and expert on seismic activity off Indonesia, is quoted as saying the risk of a major earthquake off Sumatra, possibly bigger than the one that devastated South A case study … At 2.43pm on March 11, 2011, a magnitude 9 earthquake off the east coast of Honshu, Japan’s main island, triggered a catastrophic tsunami. Japan is surrounded by tectonic plate boundaries and is highly prone to earthquakes. East Asia on Boxing Day, 2004, is extremely high. The rupture of a fault about 130 kilometres off the coast was caused by the strain of the Pacific tectonic plate being subducted under part of the Eurasian Plate, which lies beneath Japan. ¶ Tsunami warnings went out three minutes after the start of the quake, and the “It’s just like slowly drawing a bow. For hundreds of years the first wave reached the mainland 17 minutes later. The tsunami eventually affected 2000 kilometres of coast. It inundated more than 400 square kilometres of land. The highest ‘‘run-up’’ height, or the inundation height above normal sea level, was 38.9 metres. is stored as the two tectonic plates bend and deform. Then, in just a few seconds all this energy is released, generating a massive earthquake and Images, such as the one above, showed the severity of destruction; the world watched footage of water swamping protective sea walls, sweeping away cities and towns, cars and trucks, boats, bridges, roads and people. ¶ We saw explosions at the Fukushima nuclear sometimes flexing the seafloor to create a tsunami. Off western Sumatra, the power plant as the reactors failed. Radioactive leaks were confirmed in the following days and weeks. Tsunami waves propagated across the Pacific, reaching Hawaii, then the west coast of the United States. ¶ More than 15,700 people were confirmed dead and bow is drawn tight. thousands more missing. ¶ The region, right on the PacificR ing of Fire, was on alert and prepared for tsunamis, with sea barriers, well-designed buildings and tsunami evacuation training. But this was not enough to stop it becoming the costliest natural disaster ever. “A massive earthquake is due there and could happen any day.”

Counting the costs Colliding plates + strain + energy Fact file n In Australia an earthquake of the Sun, Moon and Earth. A tsunami magnitude 5.5, almost as big as can cross oceans and is caused ow can you count the cost of an earthquake? Is it by loss of life, released = earthquake Newcastle’s 1989 quake, occurs by an underwater earthquake (or property damage, the number of communities destroyed, or ruined every 15 months on average. landslide) suddenly displacing the Hlivelihoods? Earthquakes and tsunamis inflict massive tolls. arthquakes are the speeds over the molten mantle to big earthquakes. The country sea water. The earthquake and monstrous tsunami that struck Japan in 2011 became shaking and rolling of solid below. They collide, grind past each is located where the Nazca Plate n The hypocentre of an earthquake the most expensive natural disaster of all time, even more costly than Eground. They are caused by other or pull apart. They are being is being forced under the South is the place beneath the earth’s Hurricane Katrina, according to leading insurers. the sudden release of strain that has compressed and bent, crumpled American Plate at 8 centimetres surface where the rupture of the Munich Re, a worldwide reinsurance company that keeps natural disaster built up by movement in and under and pushed up. Rough edges get a year. Chile recorded an 8.8 fault begins. The epicentre is on records, estimates the economic loss in Japan at $US210 billion. Hurricane the Earth’s crust. The Earth’s outer stuck or “locked” with another plate magnitude quake in 2010. The the surface directly above the Katrina’s losses were about $US125 billion. layer, the lithosphere, which is the moving in a different direction. One strongest earthquake ever recorded hypocentre. Geoscience Australia Earthquakes and tsunamis have brought a terrible death toll over the past crust and the uppermost part of plate can be forced, or subducted, was in Chile in 1960 measuring 9.5 n The world’s greatest mountain 30 years. The quake that struck Haiti in 2010 topped the list as the deadliest the mantle, is made of huge, rigid under the other and into the molten and killing 2000. range on land is the Himalaya- natural disaster, with at least 222,570 people killed. Next was the 2004 pieces called tectonic plates. They mantle below. When the pressure The infamous San Andreas Karakoram. The longest range is Boxing Day quake and tsunami in South East Asia, in which some 220,000 are a bit like giant pieces of a jigsaw becomes too great, plates can crack fault system that runs through the 7564-kilometre Andes in South people died. In the past 100 years, the only quake to have claimed more lives puzzle. The continent of Australia or “fault”, releasing energy in what California is located along a plate America. Both were created by the was in Tangshan, China, in 1976, when about 242,000 people perished. sits in the middle of the Australian are called seismic waves. boundary. The Pacific Plate and the movement of tectonic plates. Australia’s only disastrous earthquake, in Newcastle in 1989, killed 13 Plate. There are many other plates, Moving edges of plates can get grind past n There is no such thing as people and cost about $A4.5 billion. Historically, earthquakes make up about including the Pacific Plate (the stuck against each other for years, each other in opposite directions. l Australian earthquakes in 2010. “earthquake ”. Quakes occur 13 per cent of the cost of natural disasters in Australia, with an average biggest), the Indian, African, North with stresses building up along Geologists say that one day Los in all conditions. Weather cannot yearly cost of $A145 million. American and South American sections. When they suddenly jerk Angeles could end up in Alaska. n Seismic waves travel fast, from affect the huge forces kilometres The estimate in the United States for damage to buildings through plates. Oceanic plates are on the forward, the released strain energy San Francisco suffered a 1 to14 kilometres a second, under the surface. earthquakes is $US5.3 billion a year, with 66 per cent of this figure sea floor; continental plates contain causes earthquakes. If one plate is significant earthquakes in 1906. depending on the type of rock, concentrated in California. the continents. The edges of plates being forced under another, it is not Fences, roads and rows of sediment or water they are passing Recent earthquakes around the world have inflicted a steady increase in are called tectonic boundaries. a smooth, sliding process. trees crossing the fault were cut through. The fastest seismic waves damage due to greater concentrations of population in quake prone regions Tectonic plates are under Most earthquakes occur along and moved sideways by up to take less than 20 minutes to reach and older buildings. pressure from forces deep within plate boundaries. Some, such as 8.3 metres. About 470 kilometres the opposite side of the earth. the Earth and move (centimetres quakes in Australia, are in the middle of the 1300-kilometre San Andreas n A tsunami in the open ocean a year) in different directions and of tectonic plates. Chile is prone fault broke apart and jerked forward. travels as fast as an airliner, about 800km/h. Spreading impact: the tsunami that hit Japan last year raced across the Pacific Ocean. Courtesy of NOAA Significant natural catastrophes: 1980 – February 2011 n Before electronics, scientists 10 deadliest events worldwide built huge spring-pendulum seismometers to try to record Deadly force, high speed … Period Event Affected area Overall losses Insured losses Fatalities earthquake movements. The largest ($US m, original values) one weighed about 15 tonnes. Jan 12, 2010 Earthquake Haiti: Port-au-Prince, Petionville There is one of three storeys high in it’s a tsunami 8,000 200 222,570 Mexico City that still operates. Dec 26, 2004 Earthquake, tsunami Sri Lanka, Indonesia, Thailand, n The average rate of movement San Francisco earthquake, 1906. India, Bangladesh, Myanmar, across California’s San Andreas sunamis are caused when strong, surging tides rather than continental plates around the Maldives, Malaysia 10,000 1,000 220,000 fault zone over the past 3 million n The deepest earthquakes typically ocean water is suddenly breaking waves, although the Pacific. One of the most destructive years is 4 centimetres a year. This is occur at plate boundaries where the displaced, pushed or pulled, biggest tsunamis can break with tsunamis this century was in the May 2-5, 2008 Cyclone Nargis Burma: Ayeyawaddy, Yangon, a little faster than fingernails grow. Earth’s crust is being subducted, or T Bugalay, Irrawaddy, Bago, Karen, or shaken by a change in the level a wall of white water. The energy Indian Ocean in 2004, triggered by n The East African Rift system is forced down into the molten mantle. of the seafloor. The most common forces at work are complicated an earthquake off Sumatra. Mon, Laputta, Haing Kyi 4,000 – 140,000 a 50 to 60 kilometre-wide zone of These can occur 700 kilometres cause is an earthquake that lifts by the physical nature of the Deep ocean trenches off Alaska, Apr 29-30, 1991 Bangladesh: Bay of Bengal, active volcanics and faulting that below the surface. Christchurch, 2011 Pakistan, 2005 or drops a section of ocean bed, coastline and sea floor, plus other the Kuril Islands and South America Cox’s Bazar, Chittagong, Bola, runs for 3000 kilometres. It is a rare n Antarctica has icequakes. They although some tsunamis are the factors. Some of the energy can are known for violent underwater Noakhali districts, esp. Kutubdia 3,000 100 139,000 example of an active continental rift, are similar to earthquakes but occur result of underwater volcanoes or be deflected back and forth out to earthquakes and as the sources for Oct 8, 2005 Earthquake Pakistan, India, Afghanistan 5,200 5 88,000 where a continental tectonic plate within the ice sheet. landslides. But not all underwater sea, meaning that the first surge is destructive Pacific-wide tsunamis. is moving towards splitting into two n A mass of debris from Japan’s May 12, 2008 Earthquake China: Sichuan, Mianyang, Beichuan, earthquakes trigger tsunamis. often not the worst. It is important Both the Pacific and Indian and shifting apart. tsunami is heading towards Hawaii. Wenchuan, Shifang, Chengdu, In the open ocean, tsunami not to return to a beach after the oceans now have tsunami warning n A tsunami is not a tidal wave. A Sailors have spotted TV sets, Guangyuan, Ngawa, Ya’an 85,000 300 84,000 waves are not high, at most about first tsunami wave. Most deaths are systems that involve seabed tidal wave is a shallow water wave fridges, timber and a fishing boat 1 metre, but they can be hundreds by drowning, but also from people pressure sensors, surface buoys, July-August 2003 Heatwave, drought France, Germany, Italy, Portugal, caused by the gravitational pulls of floating in the middle of the ocean. of kilometres long and they travel being flung against buildings, sonar, and satellites to send data to Romania, Spain, United Kingdom 13,800 20 70,000 very fast, at up to 800km/h. As cars, trees and other debris being early-warning centres. Australia, too, July-Sept. 2010 Heatwave, drought Russia 2,000 20 56,000 a tsunami approaches shallower washed in and sucked out. Injuries has a tsunami warning centre for June 21, 1990 Earthquake Iran: Caspian Sea, Gilan Provinz, water, it slows and becomes such as broken limbs and serious advance alerts. Manjil, Rudbar, Zanjan, Safid, Qazvin 7,100 100 40,000 steeper and higher. The first part of head trauma are common. The highest tsunami wave ever – the wave to reach the shore will be About 85 per cent of tsunamis it was 500 metres – was in 1958 in Dec 8-19, 1999 Floods, flash floods Venezuela: Vargas, La Guaira, a trough, which will appear as the are in the Pacific Ocean, generated Lituya Bay, Alaska. It was triggered Punta de Mulatos, Miranda, sea receding from shore. This is a where oceanic tectonic plates by a massive rockslide into an inlet Nueva Esparta, Yaracuy, Colombia 3,200 220 30,000 common warning sign for tsunamis. forming the ocean floor collide in the bay after an earthquake, and Source: © 2011 Münchener Rückversicherungs-Gesellschaft, Geo Risks Research, NatCatSERVICE – at March 2011 Chile, 2010 China, 2008 Most tsunamis come in like with each other or against the witnessed by fishermen in a boat.

Earthquake losses: Some of the worst … Ercis, Turkey, October 2011. Magnitude 7.2. n earthquake is usually Why are some places more damaged that others? Deaths: More than 600. Losses/costs: Not yet fully counted. How measured by its size and Underdeveloped and less prepared Chile. In 2005 in Northern Pakistan, Christchurch, NZ, February 2011. Magnitude 6.3. Aintensity. The size is the communities often suffer more when a magnitude 7.6 earthquake killed at Deaths: 181. Costs: $US20 billion. amount of energy released at the hit by natural disasters. The extent least 75,000 people. Whole villages Japan, March 2011. Magnitude 9, then tsunami. scientists source, or focus, where the sudden of the damage depends partly on and large parts of cities collapsed, Deaths: 15,500 to 20,000. Costs: $US210 billion. rupture of stressed rock takes place. things such as building construction, including many public schools and measure It may be kilometres underground. where buildings are sited and the hospitals. Pakistan, India, Afghanistan, October 2005. Magnitude 7.6. The epicentre is the point above this efficiency of relief efforts. In February Reports blamed, in part, poor Deaths: 80,300. Costs: More than $US5 billion. on the surface. 2010, a magnitude 8.8 earthquake quality construction and lack of High and dry: a child plays in front of boat after the Aceh tsunami of 2004. Chile, February 2010. Magnitude 8.8, then a tsunami in Pacific. the size of Intensity is the amount of shaking struck Chile. Although it released seismic design. Weak, adobe (mud Deaths: 507 Costs: $US30 billion. caused at a particular location, so 500 times more power than the wall) homes had been erected in quakes this will vary depending on where magnitude 7 quake that devastated many villages. This highly populated Sichuan, China, May, 2008. Magnitude 7.9. you are. Haiti a month earlier, there was a region is a seismic hotbed, a Deaths: 84,000. Costs: $US85 billion. Quakes can originate anywhere fraction of the casualties. Chile is tectonic boundary where the Indian Learn more at: Sumatra, Indonesia, December 2004. Magnitude 9, then tsunami. between the Earth’s surface and well developed with strict building tectonic plate is moving north at a n www.ga.gov.au/hazards/earthquakes.html Deaths: 220,000. Costs: $14 billion, plus more in lost livelihoods and coral about 700 kilometres below. Each codes that take into account the rate of about 4 centimetres a year. It n earthquake.usgs.gov/earthquakes/world/world_deaths.php reef destruction. one releases built-up stress in the high risk of earthquakes. More than is colliding with, and compressing, n www.bom.gov.au/tsunami/ Bam, Iran, December 2003. Magnitude 6.6. form of complex seismic waves, 220,000 people died in Haiti, 520 in the Eurasian Plate. n www.ngdc.noaa.gov/hazard/ Deaths: 30,000. Costs: About $US1 billion. which radiate through the Earth as The record of the Japanese quake in 2011. n www.abc.net.au/news/specials/japan-quake-2011/ well as on the surface. Izmit, Turkey August 1999. Magnitude 7.4. Two of these waves are called P seismographic stations around These scales are compatible and than a million earthquakes a year, is from about once a year to one Deaths: Up to 30,000. Costs: $US6.5 to $US10 billion. (primary) and S (secondary) waves. the world. Scientists study the logarithmic so that an increase of mostly minor. The smallest ones every five to ten years. Strong Papua New Guinea, July, 1998. Magnitude 7, then tsunami. They travel at different speeds and different types of waves arriving at one in magnitude means an increase that humans feel measure about earthquakes in remote areas or Produced on behalf of The Age by Deaths: more than 2000. Losses/costs: Whole villages, lagoon. in different ways through and around the stations. They use mathematical in energy by a factor of 30. So a magnitude 2. under the oceans may never be felt Clemson Text & Design. the earth. formulas to work out the size, depth magnitude 9 earthquake releases Quakes with a score of 6 or more by humans. … and the worst ever Research and writing by Seismic waves are detected, and position of a quake. almost a thousand times more are considered major. Earthquakes The magnitude 9 earthquake that Published by The Age Company Pty Ltd Leith Young Shensi, China, 1556. Deaths: More than 800,000 people, many of whom recorded and measured by Different magnitude scales are energy than a magnitude 7 event. with a magnitude of 8 or more are triggered the devastating tsunami in ABN 85 004 262 702 of 655 Collins Street, Design by Docklands 3008. were living in soft caves which collapsed. instruments called seismographs. used depending on the quake’s The United States Geological almost always highly damaging in Japan in March 2011 was the fifth Andrew Wolf Series edited by Ben Haywood, manager, www.davidclemson.co There are networks of size, depth and distance away. Survey estimates there are more any populated area. Their frequency largest in the past 110 years. Education Resource Centre