California is earthquake country, and residents of Los Angeles can now get some critical warning, when conditions are right, after a quake has started and seismic waves are heading their way.
The long-delayed system, called ShakeAlertLA, is the first of its kind in the United States.
Earthquake alert systems like this save lives, said Jeff Gorell, deputy Los Angeles mayor for public safety, as he demonstrated the application on his smartphone.
“When an earthquake starts, the first waves that go out are called P-waves,” he said. They serve as a warning and “are not the damaging, destructive waves” that will follow.
The alert system, which relies on data from seismic sensors throughout the region, could offer up to 90 seconds of warning for quakes of magnitude 5 or larger.
Even a few seconds can make a difference, said Los Angeles Mayor Eric Garcetti, as he rolled out the ShakeAlertLA smartphone app in January. Alerts let people know to drop, cover and hold on, as they are instructed to do in earthquakes.
Mexico City system
An alert system is in place in Mexico City that let residents brace for a mild shaker in early February after an earthquake struck Chiapas to the south. The quake was barely felt in the capital, but residents were ready.
The system doesn’t always help, however, and it did not with the magnitude 7.1 earthquake on Sept. 19, 2017, that killed hundreds in and around the Mexican capital. The quake’s epicenter was too close to offer warning.
Distance to epicenter crucial
Alert systems work when there’s enough distance between the earthquake’s epicenter and a center of population, said Thomas Heaton, professor of engineering seismology at the California Institute of Technology (Caltech).
“So, if you can recognize that an earthquake has started … you can give some area that’s about to be shaken strongly a heads up that says, ‘There’s an ongoing earthquake, and oh, by the way, it’s headed in your direction.’”
California is riddled with geological fault lines that periodically rupture. The largest, the San Andreas Fault, can give rise to massive temblors, including the San Francisco quake in 1906, which may have killed 3,000, according to later estimates.
A section of the same fault shifted in 1989, causing a magnitude 6.9 earthquake that killed more than 60 in Oakland and nearby communities. Smaller fault lines can also cause large temblors, including a previously unknown fault beneath the Northridge section of Los Angeles, where a magnitude 6.7 quake killed more than 60 people in 1994.
The ShakeAlertLA app offers users critical information after a temblor has started, said Deputy Mayor Gorell, “just enough so that they can digest it and then react to it, without overwhelming them with information or frightening them,” he said.
Advanced alert systems are also in place in Japan, and while the systems have limitations, authorities there say they have saved lives.
Los Angeles officials say preparing for earthquakes requires work on many fronts, including encouraging residents to prepare disaster plans and stock emergency supplies.
Preparations also require upgrades to old buildings. Los Angeles now has nearly 13,000 so-called soft-story buildings, with wide windows or doors on lower floors that need bracing. These buildings are vulnerable to damage or collapse if struck by seismic waves of a certain type or intensity.
Nearly 1,700 buildings have been upgraded to modern earthquake standards, and another 3,500 have been issued permits for retrofitting. It’s a race against time, officials say, because massive shakers rock the region periodically. The last big quake in Southern California, in 1857, reached magnitude 7.9, and could have killed thousands in a modern city.
The alert app can help, said Heaton, who noted that when the ground “starts to shake, you have no idea whether it’s going to get bigger, or whether it will stay small. Usually it stays small,” he said, “but you don’t know.”
Typhus, a bacterial infection that is sometimes life threatening, is on the rise in Los Angeles and several other U.S. cities. Public health officials say homelessness is making the problem worse and that the disease, which is associated with poverty and poor sanitation, is making a comeback in the United States.
Los Angeles County has seen 64 cases of typhus this year, compared with 53 at the same point last year and double the typical number, with a six-case cluster among the homeless in L.A. this year. Two cities in the county that have separate counts are also seeing higher numbers: Long Beach with 13 cases, up from five last year, and Pasadena with 20, a more than three-fold increase from 2017.
At a clinic in the L.A. neighborhood called Skid Row, Dr. Lisa Abdishoo of Los Angeles Christian Health Centers is on the lookout for symptoms.
“It’s a nonspecific fever,” she said, “body aches, sometimes a headache, sometimes a rash.”
This kind of typhus is spread by fleas on rats, opossums, or even pets and is known as murine typhus, from the Latin word for “mouse.”
The risk is higher when people live on the streets in proximity to garbage, but the disease seems to be spreading through the Southern United States.
Not the typhus of WWI
“It’s never been considered a very common disease,” said Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, “but we seem to see it more frequently. And it seems to be extending across from Southern California all along the Mexican border into southeastern Texas and then into the Gulf Coast in Florida.”
Texas had 519 cases last year, said spokeswoman Lara Anton of the Texas Department of State Health Services. That’s more than three times the number in 2010, with clusters in Houston and Galveston. No figures for this year have been released.
This is a separate disease from typhoid fever and is not the epidemic form of typhus that caused hundreds of thousands of deaths in war time. That type, called epidemic typhus, is carried by body lice and often spreads in conflict zones. It led to millions of deaths in World War I alone.
Flea-borne typhus, the kind seen in California and Texas, is serious but often clears up on its own and responds to an antibiotic, Abdishoo said.
“It seems to get better a little faster if you have the treatment,” she said. “But there are cases where people have had more severe complications — it’s rare, but getting meningitis, and even death,” she cautioned.
Migration, urbanization, climate change
The reason for increased typhus numbers is uncertain, but it may be linked to migration, urbanization and climate change, said Hotez, the disease specialist. In some parts of the world, typhus is still linked to war and instability, “in the conflict zones in the Middle East, in North Africa, Central Asia, East Africa, Venezuela, for instance with the political instability there,” he said.
Murine typhus is one of several diseases on the rise in the southern United States, Hotez said.
“Others include dengue, now emerging in southern Texas and Florida, the Zika virus infection, Chikungunya. We have a huge problem with West Nile virus,” he added, and Chagas disease, a condition usually seen in Latin America.
A report in May from the U.S. Centers for Disease Control and Prevention found that such “vector-borne” diseases, transmitted by ticks, fleas or mosquitoes, more than doubled in the United States between 2004 and 2016.
Hotez says they are on the rise in many industrial nations with crowded cities and pockets of poverty.
Skid Row physician Abdishoo says flea-borne typhus is still uncommon on the streets of Los Angeles, but “it has us all on high alert for this illness that we don’t necessarily think too much about. We want to be vigilant,” she added, “when you see a communicable disease on the rise.”
Officials in Los Angeles say they are working toward housing for the county’s 53,000 homeless residents to relieve conditions that help give rise to typhus and other diseases. Voters approved funding in 2016 and 2017 to finance the efforts. (VOA)