Category: Environment

BBC News

Turkey earthquake fault lines mapped from space

Jonathan Amos – BBC Science Correspondent – February 10, 2023

It seems almost insensitive to start to have a deep dive into the science behind Monday’s earthquake events in Turkey.

More than 22,000 people are already confirmed dead and an unknown number still lie trapped, with the window for their rescue closing rapidly.

And yet the science will go on. The insights gleaned from this event will save lives in the future.

Take a look at the map on this page. It is the most precise yet produced of how the ground lurched in response to the enormous energies that were unleashed.

The data behind it was acquired in the early hours of Friday by the European Union’s Sentinel-1A satellite as it traversed north to south over Turkey at an altitude of 700km (435 miles).

The Sentinel carries a radar instrument that is able to sense the ground in all weathers, day and night.

It is routinely scanning this earthquake-prone region of the world, tracing the often very subtle changes in elevation at the Earth’s surface.

Except, of course, the changes on Monday were not subtle at all; they were dramatic. The ground bent, buckled and in places ripped apart.

• Live: BBC coverage of the Turkey quakes
• Why was the earthquake so deadly?
• How do rescue teams reach people under rubble?

Researchers use the technique of interferometry to compare “before” and “after” views. But you do not really need to be an expert to see the consequences for Turkey in the latest Sentinel map.

The red colours here describe movement towards the satellite since it last flew over the country; the blue colours record the movement away from the spacecraft.

It is abundantly clear how the ground has been deformed along and near the East Anatolian Fault line.

For both the Magnitude 7.8 quake that struck first on Monday at 01:17 GMT and the Magnitude 7.5 event at 10:24, the motion is “left-lateral”. That is to say: whichever side of the fault you are on, the other side has moved to the left. And by several metres in places.

The shocking thing is that the lines of rupture have gone right through settlements; in lots of places they will have gone right through buildings.

The Sentinel map will help scientists understand exactly what happened on Monday, and this knowledge will feed into their models for how earthquakes work in the region, and then ultimately into the risk assessments that the Turkish authorities will use as they plan the recovery.

There is sure to be a lot of discussion about how the two major tremors were related and what that could mean for further instability.

The map was processed by the UK Centre for Observation and Modelling of Earthquakes, Volcanoes and Tectonics (Comet). Its director, Prof Tim Wright, said the Sentinel observations vividly brought home the scale of the forces involved.

“News outlets always show earthquakes as ‘the epicentre’, as if it is a single point source (like a bomb). Actually, all earthquakes are caused by slip on extended faults, and the bigger the quake the bigger the fault that ruptured,” he told BBC News.

“We can map those ruptures with satellites because the ground around them is displaced, in this case by up to 5m or 6m. The rupture of the first event was 300km or so long and the second big event ruptured another 140km or so of a different fault. To put those distances in context, London to Paris is roughly 345km.

“Damage will be highest near the fault but of course spreads over a wide region either side of the fault, too. It’s absolutely horrific.”

In the era before satellites, geologists would map earthquake faults by walking the lines of rupture. It was a laborious process that naturally also missed a lot of detail. Radar interferometry from space was developed in the 1990s, and in recent years it has become a particularly compelling tool.

In part that is down to the quality of the sensors now in orbit, but it is also the result of more powerful computers and smarter algorithms.

It is possible today to get a data product on to the computers of experts, ready for analysis, within hours of a satellite making an overhead pass. Comet, unfortunately, had to wait several days for Sentinel-1A to be in the right part of the sky to get an optimal view of Turkey. But this will improve as more and more radar satellites are launched.

“By the end of the decade, we should be able to do this kind of analysis within a day of most damaging earthquakes, and then we would be more useful for the relief effort. As things stand, we are of course outside the 72-hour window for search and rescue,” Prof Wright said.

The Washington Post

Daunting medical issues for earthquake survivors are just beginning

David Ovalle – February 9, 2023

As international medical teams stream into the earthquake-ravaged areas of Turkey and Syria, the injuries they are encountering are horrific but no surprise: broken bones, arms and legs crushed by collapsed buildings, infected gashes.

But that’s only the beginning for doctors and paramedics working feverishly to save lives in a disaster that has already claimed more than 20,000 people, experts say.

In coming weeks, as search efforts turn to the grim task of recovering bodies, countless survivors will need medications for high blood pressure, diabetes and asthma left behind in the rubble. Many who are pregnant will give birth in makeshift shelters and refugee camps. Cancer patients will go without treatment.

Freezing temperatures mean survivors in thrown-together shelters face hypothermia or frostbite. Close quarters in shelters could also lead to the spread of the coronavirus and other respiratory viruses.

And there’s another looming risk: waterborne diseases such as cholera, which had already appeared in the affected war-torn region of northwest Syria because of poor water quality and sanitation.

“It’s a horrible situation. You can’t do everything you want to do and you have to adapt to a whole different way of treating people. It’s a mentally and morally taxing situation,” Thomas Kirsch, a professor of emergency medicine at the George Washington University School of Medicine and Health Sciences, said of the coming challenges for medical workers.

Paul Spiegel, director of the Center for Humanitarian Health at the Johns Hopkins Bloomberg School of Public Health, said the time period after the search-and-rescue efforts will be crucial, if less dramatic.

“You likely will save a lot more people by ensuring you have surveillance and thinking about continuing care and supplies,” he said.

Those efforts are already being spearheaded by the Turkish government, the World Health Organization and other aid groups that regularly send emergency teams into earthquake zones.

The challenges to providing medical care are especially daunting in Turkey and Syria, which was rocked by a 7.8-magnitude quake early Monday morning, and a second one hours later that was recorded at 7.5.

The disaster toppled hospitals and other medical facilities that would have been crucial for treating those injured in building collapses, not to mention other ailments. Buckled and impassible roads won’t make it any easier for medical organizations, said Kirsch, who has worked extensively in disaster zones, including in Haiti after it was devastated by a 2010 earthquake.

“The logistics and coordination of the health-care response is really a problem,” he said.

Syria is of particular concern because of the destruction of its health care infrastructure after years of civil war, Iman Shankiti, the WHO’s representative in the country, told reporters Wednesday.

“Definitely, the health needs are tremendous. It’s important to note that the health system has suffered for the last 12 years, and continues to suffer and continues to be strained by the ongoing emergencies, and the last one is this earthquake,” Shankiti said.

The WHO said it was sending three flights with medical supplies to both countries, including trauma kits, from a logistics hub in Dubai. It also has released $3 million in funding.

The Israeli Defense Forces has said it is setting up a field hospital in Turkey.

Nongovernmental groups will also be key. Doctors Without Borders, which was already in northwest Syria, said it is continuing to support seven hospitals, health-care centers and a burn unit in the area.

Americares, a Connecticut-based health-focused relief group, has already sent a shipment of hygiene kits, IV fluids and some chronic-disease medicines. A four-person team is already on the ground in southern Turkey.

“In the coming days, there’s going to be a tremendous need for those chronic-need medicines,” said Julie Varughese, the organization’s chief medical officer.

Project Hope, a global health and humanitarian aid organization, is also in Gaziantep, Turkey, a city hit hard by the earthquakes. Like many medical relief organizations, it is assessing what help each area will need with short- and long-term health care, as search-and-rescue operations continue to look for survivors.

The organization’s humanitarian health adviser, Pranav Shetty, fears that in coming days, doctors will see many of the same medical conditions that unfolded in Haiti after its devastating earthquake in 2010.

Doctors will need to work quickly to remove dead tissue from wounds, lest it lead to dangerous infections, he said.

Another pressing concern is what’s known as “crush syndrome,” which happens when survivors are pulled from the rubble, releasing pressure on muscles and releasing toxins from damaged tissue. That can wreak havoc on survivors’ kidneys, requiring dialysis – no easy task to provide when hospitals are destroyed.

“That’s a pretty robust intervention that requires a lot of resources,” Shetty said.

Still, the everyday maladies may end up being a wider problem as the months pass.

Kirsch, of George Washington University, said foreign medical assistance will be needed to help with everyday conditions such as diabetes, heart attacks and strokes.

“Turkey has a pretty strong health-care system, so its recovery will be better than a lot of less economically robust countries,” he said.

And both countries will need to pour resources into mental health treatment, not just for survivors but for medical personnel who have been overwhelmed ministering to those in need.

“At times you make decisions about life and death you wouldn’t have to make in other situations,” Kirsch said of medical personnel in earthquake zones. “That’s the struggle early on.”