The earthquake threat in California is little different from that posed by the Sagaing fault line that slices north to south through the middle of Myanmar.
Earthquakes hit California and Myanmar every day, but while most do not cause damage or loss of life, experts say the day will come when big quakes will cause major disasters and loss of life.
Governments must prepare for that day now.
The key to surviving an earthquake and reducing the risk of death or injury lies in identifying potential quake areas, establishing proper building code and putting in place comprehensive disaster response plans that involve families, schools, government agencies and the police and military.
Myanmar is well on its way to understanding the threat of earthquakes and preparing the people and the government to respond appropriately.
During a major earthquake, you may hear a roaring or rumbling sound that gradually grows louder. You may feel a rolling sensation that starts out gently and, within a few seconds, grows violent, or you may first be jarred by a violent jolt. A second or two later, you may feel shaking and find it difficult to stand up or move from one room to another.
California’s San Andreas fault line
Myanmar can learn about earthquakes from California, which recorded 512 earthquakes in the past month, ranging from a high of 4.2 on the Richter scale. The Richter scale, developed in the 1930s, is a base -10 logarithmic scale, which defines strength of a quake’s magnitude.
Earthquakes are usually caused when rock underground suddenly breaks along a fault line. When two blocks of rock or two plates are rubbing against each other, they stick a little, causing seismic waves, which shake the ground. During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again.
The spot underground where the rock breaks is called the focus of the earthquake. The location directly above the focus (on top of the ground) is called the epicenter of the quake.
California’s San Andreas Fault (SAF) runs about 700 miles along California in a north to south direction, passing near San Francisco and Los Angeles. It shares tectonic plate characteristics with the Sagaing Fault.
The strongest SAF quake recently was magnitude 7.3, in 1992, centered in Lander, about 130 miles east of Los Angeles. Three people died and 400 were injured, a testament to California’s high level of preparedness and the advanced building codes which offer greater quake protection. Experts say “The Next Big One” could occur any day.
Sagaing faultline and history
Myanmar has had 24 earthquakes in the past year. Most were in the magnitude 4.5 range or lower.
In 2011, a 6.9 magnitude quake was centered in eastern Shan State. The death toll was estimated at around 80 people, and the US Geological Survey's population exposure data estimated final damage from the earthquake was most likely to be slightly under $100 million.
In 2012, the Shwebo 6.8 magnitude quake, caused by the Sagaing Fault, struck an area about 100 km north of Mandalay. An estimated 26 people died and significant damage occurred.
The Sagaing Fault is a major fault in running north to south. It passes through populated cities of Mandalay, Yamethin, Pyinmana, the capital, Naypyidaw, Toungoo and Pegu before dropping off into the Gulf of Martaban, over 1200 kilometers distance.
The fault ruptured in 1930, causing a magnitude 7.3 quake and likely a tsunami at Bago, causing more than 500 deaths.
Myanmar’s biggest earthquake, measuring 8.2 on the Richter scale, took place in 1912 along the Kyauk Kyan Fault in northern Shan State, another of the country’s main faults (the third is the Rakhine Fault).
The Kyauk Kyan fault is 800 kilometres long, stretching from Shan State to southern Kayah State.
"There have been earthquakes in the past, but the impact was not substantial in areas that were sparsely populated, but if a big earthquake happened to a big city, that would be very devastating because they are not very prepared," says Peer nan Towashiraporn, a senior project manager and earthquake expert at the Asia Disaster Preparedness Center (ADPC) in Bangkok, citing poor building construction quality, building types, materials, and construction methods.
Cities are growing and the risks are increasing.
Among predictions of imminent Myanmar earthquakes is a study by researchers in Japan, who warn that an earthquake with a magnitude of up to 7.9 could shake central Myanmar, near the newly-built capital, Nay Pyi Taw, at any time.
"But I'm not worried about the new capital, as the buildings there were well built," said Soe Thura Tun, secretary of the Myanmar Earthquake Committee.
Tun told the Irin humanitarian news website he’s more concerned about the nearly 5 million inhabitants of Yangon, who mostly reside in old buildings constructed in a zone considered to have strong seismic potential. The Sagaing Fault, the Dedaye Fault and the Western Bago Yoma Fault are all close by the former capital.
In February, earthquake experts met in Yangon to discuss plans to prepare for the day when an earthquake will strike the city. The project will include a “hazard map” that identifies neighbourhoods believed to be at greatest risk.
Bijay Karmacharya, head of agency at the United Nations Human Settlements Programme – said that preparations for an earthquake were urgently needed in Yangon, whose population has increased 10-fold in the past 80 years.
Five hundred people died in a magnitude 7.0 earthquake in 1930 in Bago Region, he said, and 50 died in Yangon but at the time the city’s population was just 400,000.
“Yangon’s population is now more than 5 million and the city is undergoing rapid transformation. An earthquake now would have a significant impact,” he said.
U Myo Thant, a lecturer at Yangon University and secretary of the hazard section of the Myanmar Earthquake Committee, told the Myanmar Times the project would identify seismic sources, and calculate seismic hazards. “The result will be maps showing active faults, engineering considerations, liquefaction potential and earthquake potential,” he said.
As a member of the Myanmar Earthquake Committee, Tun said the hazard and risk maps are essential to disaster risk reduction.
“With hazard and risk maps, the government knows where the priority areas for hazard management are and the maps will prepare the city for earthquake disasters,” he said.
Based on the information, appropriate building codes can be put in place and officials can identify open areas where people can gather safely.
Yangon lies close to the Sagaing Fault, the most active fault in the country.
The 18-month project was supported by UN-Habitat – through the Myanmar Consortium for Community Resilience, under the European Commission Humanitarian Aid department’s Disaster Preparedness Programme – and the Norwegian Ministry of Foreign Affairs.