On the disparity of deaths and damages from earthquakes with similar magnitudes, depths, and depths: A geoclimatologist explains the analogy to Jell-O
Earthquakes can be similar in appearance to Jell-O. A simple, yet often used analogy is that if you’re sitting in a valley or basin, it acts like a bowl of gelatin and it will shake more than surrounding rock.
The geology of the area matters as well, according to a sociologist with the US Geological Survey. “What the topography is, it definitely matters.”
The frequencies of earthquakes are low and high. The ground has low frequencies if it vibrates slowly. If the ground vibrates quickly, it’s more of a high frequency.
Hough explains further that while the waves themselves travel the same way, in the sense that a P wave is still a P wave, and a S wave is still a S wave, however, their speeds and amplitudes will change depending on the rock type.
Earthquakes occur on every continent in the world — from the highest peaks in the Himalayan Mountains to the lowest valleys like the Dead Sea to the bitter cold regions in Antarctica. However, the distribution of these quakes is not random.
The disparity of deaths and damages from two earthquakes with similar magnitudes and depths is puzzling. The answer has a lot to do with plate tectonics and how buildings are constructed.
The 7.8 magnitude earthquake in southern Turkey is considered the strongest earthquake to hit the world in the last decade, according to the AP. A 2011 earthquake in Japan triggered a tsunami that killed more than 19,000 people.
The depths were also 888-609- 888-609- 888-609- 888-609- 888-609- The earthquakes in Haiti and California were both over eight miles deep. 8 miles does not seem shallow, but it’s in terms of earthquakes. A shallow earthquake is defined by the Geological Survey as one that is less than 73 miles deep. The shallower an earthquake is, the more likely damage will occur since it is closer to the surface.
New Perspectives on Earthquake Propagation and Frequencies in North America and the West Coast of the United States. I. California’s Terrain
Low frequencies mainly affect multistory buildings in particular. The bigger the buildings that will be affected, the lower the frequencies. High frequencies can affect small buildings.
In Haiti and other island nations, you have rocks that rise from the surface, on which houses are built, to much softer zones which can actually amplify the seismic waves.
The East Coast has a younger crust. When an earthquake happens, it reverberates like the waves produced by a ripple in water. The waves can travel hundreds of miles in the East than in the state of California.
There are many variables to California’s terrain. There are mountain ranges, valleys and beaches. When an earthquake occurs in California, the energy is scattered around and doesn’t make it to the ground very far.
Earthquake-Soil-Rock-Types in Kathmandu, Haiti: Is There a Topographical Aspect?
Haiti also has a topographical aspect to it. The low lying areas of port-au-Prince are mostly at sea level. But just 10-15 miles away, the elevation increases several thousand feet into a more mountainous terrain with harder rock at the surface.
“In Kathmandu in 2015, there was a booming amplification because it’s a lake bed zone, but the valley was sloshing back and forth with a five-second period, and you can see that on closed captioned TV. You had things that left one side, and then went back on the other. It was a slow motion, but it was strong because of the lake bed. The effect on buildings is determined by the size of the buildings.
The waves in the ocean are not as big as a big swell in the ocean but they will be more damaging if they attack the boat. For a large ship on a big swell its bow would go up while the stern goes down, generating stress within the boat. If the ship is smaller than the swell, the entire ship just goes up and down.
Ground failure, which is earthquake triggered landslides and liquefaction, is one of the contributors to earthquake damage.
“It takes time for first responders and experts to survey the actual damage in the area, so our product provides early estimates of where to focus attention and response planning,” according to the USGS.
The models do not predict specific occurrences, though they provide initialawareness, overall extent, and indicate areas that are most likely to have occurred.
Source: https://www.cnn.com/2022/12/20/weather/earthquake-soil-rock-types-xpn/index.html
The 2010 Haitiquake left many people without electricity and dozens of homes and businesses in Humboldt County, California, out of power
The strong shaking from the 2010 Haiti quake caused more than 23,000 slides on the island of Hispaniola.
“There is something called non-linearity, and it turns out that if you try to shake soft sediments really hard, it’s not a bowl of Jell-O as much as it is a sandbox,” Hough says.
For example, Hough explains that if you shake a sandbox really hard, it’s going to stop acting like rock. Things will shift around at a larger size, which will absorb energy.
“If the sand is water-saturated, as I imagine it is in many places in India, it can start to behave like a liquid. The shaking can cause some damage, but it can also be a good thing if the ground starts behaving like liquid, and that’s if the structure isn’t collapsing. It looks like sitting on quicksand. Even a well-built building can just tip over,” Hough told CNN.
A 6.4 magnitude earthquake struck Northern California’s Eureka area early Tuesday, according to the US Geological Survey, shaking people from their sleep, leaving thousands without electricity and damaging at least one bridge.
Most homes and businesses in Humboldt County were out of power early Tuesday. More than 71,000 outages were reported shortly after 4:30 a.m. PT – out of 99,000 customers tracked in the county – according to utility tracker PowerOutage.us.
The earthquake that caused Tuesday’s temblor in Humboldt County on December 20, 2021 left a mess in her home
“Once the shaking finally stopped, we got our flashlights and phones and looked around. Everything was in shambles.” Pickett Monolias said. “Things you wouldn’t expect to have fallen over or broken did. An entire cabinet in the bathroom fell over and broke apart.”
A video that she posted to Twitter shows that a number of things spilled onto the floor of her home. This is a big one. The power is out. The house is a mess.
The temblor left cracks in a bridge in Ferndale and debris on its roadway, the California Highway Patrol said. CNN affiliate KRCR reported that police had closed the span.
The 6.0 magnitude earthquake that occurred one year ago is what caused Tuesday’stemblor. That quake struck just off Humboldt County’s Cape Mendocino on December 20, 2021, and caused minor damage to buildings in the area.
Seyhun Puskulcu, a seismologist and CEO of the Istanbul earthquake foundation, says he is still alive
Turkey’s government said search and rescue teams have pulled more than 8,000 people from underneath the rubble of thousands of toppled buildings in the past two days. Concerns increased that survivors might die due to the worsening weather conditions in the region.
More than 11,000 people have died as a result of the early Monday morning earthquake, The Associated Press reported. The government in Turkey reported about 8,500 deaths from the earthquake. In Syria, the death toll had reached at least 1,200 in government-held areas.
Seyhun Puskulcu, a seismologist and coordinator of the Turkish Earthquake Foundation, based in Istanbul, says people in Turkey are well aware of their vulnerability to earthquakes. “This wasn’t a surprise,” says Puskulcu, who last week was touring the cities of Adana, Tarsus and Mersin, and areas of western Turkey, delivering workshops on earthquake awareness.
“I know my son is inside and I think he’s still alive. She toldNPR that his brother dug with his hands to find him. Hours later, as diggers chipped away at the ruins of the building, rescuers found Sedat’s body and wrapped it in a blanket for his mother to say goodbye.
Seismic activity in the Gaziantep province of Turkey after the 2010 September earthquake: a study by the Open University and the Middle East Technical University
Aid groups consider the first 72 hours after a natural disaster as crucial for rescuing survivors. In neighboring Syria, the government has blamed Western sanctions for hampering relief efforts, but the U.S. says sanctions do not include humanitarian assistance. Regardless, northern Syria lacks the heavy equipment and other infrastructure to come to the aid of the hundreds of thousands displaced by this disaster, and the only U.N.-authorized road from Turkey to that region has been damaged by the quake.
Iran, Libya, and the United Arab Emirates have sent hundreds of millions of dollars worth of aid to Syria, and dozens of countries have sent aid to Turkey, including more than 5,000 rescue workers who are arriving in the disaster area.
More than 380,000 people have been temporarily displaced from Turkey as a result of the disaster, but the emergency management agency has set up more than 70,000 tents to house them.
The earthquake and its aftershocks have flattened buildings and sent rescuers digging through concrete debris to find survivors, with the death toll expected to increase further. Nature spoke to four researchers about the seismic activity in the region and what the next few days will bring.
The Anatolian plate has two major faults, the East and North Anatolian Faults. The southern rim of Eurasia has been squeezed out towards the west by the moving plates that carry Arabia, says David Rothery, a geoscientist at the Open University. The East Anatolian Fault has Turkey moving west at a rate of about 2 centimetres per year. “Half the length of this fault is lit up now with earthquakes.”
The epicenter of the earthquake was 26 kilometres from the city of the same name, in Turkey’s Gaziantep province. Around 4 kilometres southeast of Ekinz in the Kahramanmara province, there was a magnitude 7.5 earthquake.
In a study1 published last March in Soil Dynamics and Earthquake Engineering, Arzu Arslan Kelam at the Middle East Technical University, Ankara, and her colleagues suggested that the centre of the city of Gaziantep would experience medium-to-severe damage from a magnitude-6.5 earthquake. This is because most existing buildings are low-rise brick structures that are constructed very close to each other.
Things are worse in Syria, where more than 11 years of conflict have made building standards impossible to enforce. The earthquake struck Syria’s northwestern regions, with buildings collapsing in Aleppo and Idlib. War-damaged buildings in Syria have been rebuilt using low-quality materials. “They might have fallen down more readily than things that were built at somewhat greater expense. We’ve yet to find out,” he adds.
The forecast for tonight’s weather in the region is very cold. That means that people who are trapped in the rubble, who might be rescued, could well freeze to death. These are the hazard that continues, he adds.