Friday, April 19, 2019



Tiny earthquakes happen every few minutes in Southern California

The 1994 Northridge earthquake in Southern California, photo from NPR.

Detecting very small earthquakes is notoriously difficult. The rumbling of the ocean, a passing car or even the wind can feel a lot like a minor quake to the sensors that blanket seismically active parts of the U.S.

"They have a robust seismic network in Southern California," explains Daniel Trugman, a seismologist at Los Alamos National Laboratory and an author of the study. But while 180,000 might seem like a large number of quakes, there were many, many more hiding undetected in the data.

When Trugman and his collaborators re-analyzed the data using a powerful array of computer processors, they found evidence of 10 times as many earthquakes — 1.81 million temblors in a decade, or roughly one tiny earthquake every 3 minutes or so. (Full Story)



Scientists uncover California’s hidden earthquakes

The new study, published this week in Science, adds nearly two million earthquakes to the catalogue of total seismic events in Southern California over the past decade. Although the newly known quakes were imperceptible to humans, the findings help fill gaps in the earthquake record, shedding light on the geophysical processes that lead to the dreaded “Big Ones.”

Although Daniel Trugman at the Los Alamos National Lab notes that the hints the study gleaned on how foreshocks work are far from definitive, he is confident the new data set will allow scientists to better understand what precisely kicks an earthquake into high gear. And that may one day help scientists forecast earthquakes. “If we could really predict when the next big earthquake will occur, we’re in business—that’s the Holy Grail in seismic hazard analysis,” Trugman says. “I definitely wouldn't say we're there yet, but it's this type of work that's going to hopefully push us forward.” (Full Story)

Also from Scientific American this week:

How Long Do Neutrons Live?


Illustration from SciAm.

Physicist Zhaowen Tang of the Los Alamos lab described how researchers could put a particle detector inside a bottle neutron trap and count neutrons using both methods [beam and bottle]. His team has acquired funding to start building the device.

Another possibility is that the beam and bottle approaches have been measuring the neutron lifetime correctly, but that some unseen factor accounts for the discrepancy between the two. A leading idea is that neutrons might occasionally decay into not just protons but also dark matter, the mysterious unseen material that makes up much of the Universe’s matter. (Full Story)



Stopping an Earth-bound asteroid in its tracks

 
Kathy Plesko and a Bennu impact computer model, LANL image.

As a research scientist at Los Alamos National Laboratory, I study what happens to the atmosphere and crust of a planet when an asteroid or comet hits and possible ways to stop that from happening. I use the supercomputers at Los Alamos, some of the fastest in the world, to run high-fidelity simulations to accurately model the physics of an impact. These simulations are constantly updated with cutting-edge data from NASA missions and Earth-bound laboratory experiments.

Our first what-if case study focused on asteroid Bennu, the target of the NASA OSIRIS-REx mission. Bennu is about as wide as the Empire State Building is tall, and weighs as much as 800 aircraft carriers. (Full Story)



Unlocking secrets about the origin of the universe

Scientists and engineers from more than 70 organizations have come together to develop the tools to unravel the microscopic secrets hidden within quark-gluon plasma.

Los Alamos researchers are contributing to the project by designing an advanced tracking detector based on a new type of sensor system called MAPS, short for Monolithic Active Pixel Sensor. When the collider produces quark-gluon plasma in the sPHENIX experiment in several years, a new tracking detector will be there to capture the first measurements of the plasma’s internal structure using heavy quarks. (Full Story)



Microbes living in different parts of the human body can still swap genes

Microbes that live in the human gut. From Tech Times.

The research revealed that the most common transfer of genes happened between microbes that are most closely related to each other regardless of whether they are in the same sites or not.

"Some of these could be very old gene transfer events that happened before the microbes colonized the human body," explained Arshan Nasir, a distinguished fellow at the Los Alamos National Laboratory in New Mexico. "It also could be that some bacteria colonize different human body sites at different time points in an individual's lifespan. The others could be the result of the transfer of bacterial DNA from one site to another, perhaps through the blood." (Full Story)



Q&A: Creating ‘smart’ microbial bionsensors

 
The implications of this smart microbial cell concept are to offer an advanced platform for high throughput screening for enzyme discovery, design, and evolution. The approach, which comes from Los Alamos National Laboratory, can be translated to screening of metagenomic samples, rational enzyme design, or directed evolution of known enzymes. The technology is adaptable to a single enzyme, or a pathway, or global optimization of an industrial strain. To discover more, Digital Journal spoke with researcher Ramesh Jha. (Full Story)

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