• Japan tsunami debris confirmed in California

    Redwood Coast Tsunami Working Group

    Examining the Japanese skiff that washed up near Crescent City, Calif., on April 7, 2013. This is the first verified item from the Japan tsunami to appear in California.

    By Douglas Main
    LiveScience

    A small skiff recently washed ashore near Crescent City, Calif. But this was no ordinary ship — it floated there all the way from Japan, dislodged from its native land more than 25 months ago by a monster tsunami, government scientists have confirmed.

    It's the first confirmed piece of debris to wash up in the state of California from the Tohoku earthquake and tsunami that hit Japan on March 11, 2011, according to the National Oceanic and Atmospheric Administration (NOAA).

    The Coast Guard and local sheriff's office removed the ship after it was spotted, and staff at Humboldt State University in northwestern California helped translate the Japanese writing on the boat. Officials then traced the boat to Takata High School, located in Japan's Iwate prefecture, an area devastated by the tsunami, NOAA reported. 

    The 20-foot (6 meters) skiff was covered in gooseneck barnacles, a common type of filter feeder that makes itself at home on stuff that floats in the open ocean. It wasn't immediately clear whether this boat carried invasive species, which had been seen with other pieces of Japanese tsunami debris that have washed up on the West Coast.

    One ship that recently washed onto the shore in Long Beach, Wash., for example, contained an estimated 30 to 50 species of plants and animals, including potential invasive species. In a sealed compartment in the back of that ship, scientists found five live striped beakfish — “a species native to coral reefs mainly in Japanese waters (and) sometimes found in Hawaii, but certainly not in the cold waters of the Pacific Northwest coast," NOAA reported.

    To date, 26 other pieces of Japanese debris have washed up in Oregon, Washington, Hawaii, Alaska and British Columbia.

    The tsunami dragged some 5 million tons of debris into the Pacific Ocean, according to Japanese government estimates. Much of it likely sunk shortly thereafter, but about 1.5 million tons floated away from Japan's coast, and this tsunami debris is still washing up far afield.

    Email Douglas Main or follow him @Douglas_Main. Follow us @OAPlanet, Facebook or  Google+. Original article on LiveScience's OurAmazingPlanet.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Sea lion strandings climb; scientists have a theory

    Pacific Marine Mammal Center

    This year, an unusually high number of sea lion pups have stranded on southern California's shores, overwhelming marine mammal rehab centers.

    By Megan Gannon
    LiveScience

    Scientists still don't know why nearly 1,300 sickly sea lions have beached themselves on the shores of southern California since the beginning of the year. However, they think some weird oceanic phenomenon may be blocking off the sea lion pups' source of food, scientists reported Wednesday.

    The stranded sea lions — mostly pups born last summer — are typically turning up alive, but severely emaciated, some weighing less than 20 pounds (9 kg) when they should be well over 50 pounds (22 kg), marine officials say.

    The National Oceanic and Atmospheric Administration (NOAA) declared an "unusual mortality event" last month in light of the spike in strandings. Since the beginning of the year, 1,293 sea lions have washed ashore from San Diego County to Santa Barbara County. That's more than five times higher than the region's historical average of 236, averaged from the same period of time (January through April) from 2008 to 2012, said Sarah Wilkin, NOAA's marine mammal stranding coordinator for California. [Marine Marvels: Spectacular Photos of Sea Creatures]

    The problem is most pronounced in Los Angeles County, where 459 strandings have been reported this year as of April 14. During the same period last year, 60 strandings were reported.

    California hasn't seen a spike in starving sea lions on this scale since El Niño warmed up Pacific waters in 1998. El Niño conditions can diminish the upwelling of cold, nutrient-rich water needed to support large populations of fish that are eaten by other animals like sea lions.

    "In the words of some of the other biologists, if this was an El Niño year, it would still be overwhelming but it wouldn't be all that surprising," Wilkin said. But this isn't an El Niño year, so the mystery remains.

    Wilkin told reporters Wednesday that biologists think an unseen oceanographic or environmental phenomenon is likely cutting the sea lion pups' supply of food, much like El Niño would. While adult sea lions and other marine mammals may be able to adapt their feeding habits in the face of a shortage, pups are more limited in how far they can travel for food and what they can eat.

    A localized anomaly like that happened in 2009, causing an above-average number of strandings.

    "The prevailing onshore winds did not blow as strongly as they usually do and it resulted in a lack of upwelling, which created a foraging difficulty for California sea lions," Wilkin explained.

    Toxic algae blooms and infectious disease outbreaks also can trigger mass pup strandings. Researchers don't have evidence that either of those factors are contributing to the problem this year, but scientists are still waiting to see if tests on blood and tissue samples turn up bacterial, viral and other infectious agents or radioactive traces.

    In a good sign, there has been a slowdown in the number of stranded, starving sea lion pups being admitted to rehab facilities, Wilkin said. At the same time, other animals are washing up. Northern elephant seals have just entered their stranding season and biologists have found a few adult female sea lions suffering from seizures, suggesting they may have been poisoned by the neurotoxin domoic acid, which is produced by multiple species of the genus Pseudo-nitzschia, a type of algae.

    Follow Megan Gannon on Twitter and Google+. Follow us @livescience, Facebook and Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • 'Lost' tectonic plate found -- and mystery is solved

    Forsyth lab / Brown University

    The Isabella anomaly in California is in line with known remnants of the long-gone Farallon plate.

    By Stephanie Pappas
    LiveScience

    A tectonic plate that disappeared under North America millions of years ago still peeks out in central California and Mexico, new research finds.

    The Farallon oceanic plate was once nestled between the Pacific and North American plates, which were converging around 200 million years ago at what would become the San Andreas fault along the Pacific coast. This slow geological movement forced the Farallon plate under North America, a process called subduction.

    Much of the Farallon plate got pushed down into the mantle, the flowing layer below the Earth's crust. Off the coast, parts of the plate fragmented, leaving some remnants at the surface, stuck to the Pacific plate.

    Now, new research published Monday in the journal Proceedings of the National Academy of Sciences finds that these pieces of Farallon plate are attached to much larger chunks at the surface. In fact, part of the Baja region of Mexico and part of central California near the Sierra Nevada mountains sit upon slabs of Farallon plate.

    The finding solves a mystery of California geology. Earth scientists use seismic waves (either recorded from earthquakes or created with dynamic charges or other methods) to map out the region beneath the Earth's surface. Softer and hotter materials slow seismic waves down. The waves move faster through stiffer, cooler material.

    In California, these seismic surveys revealed a large mass of cool, dry material 62 miles to 124 miles (100 to 200 kilometers) below the surface. This strange spot was dubbed the "Isabella anomaly." [7 Ways the Earth Changes in the Blink of an Eye]

    Despite many theories, no one had nailed down exactly what caused the Isabella anomaly. Then researchers discovered another anomaly (where the researchers saw a change in seismic wave speed where one wasn't expected) under the Baja Peninsula, directly east of some of the known remains of the Farallon plate. The proximity led Brown University geophysicists Donald Forsyth and Yun Wang (now at the University of Alaska) to suspect they might be related.

    Near the eastern edge of the anomaly, the researchers found volcanic rock deposits called high-magnesium andesites. These are usually linked to the melting of oceanic crust, suggesting that this is the spot where the Farallon plate broke off and subducted, melting into the mantle.

    A re-examination of the Isabella anomaly found that it, too, lined up with known Farallon fragments.

    "This work has radically changed our understanding of the make-up of the west coast of North America," study co-author Brian Savage of the University of Rhode Island said in a statement. "It will cause a thorough rethinking of the geological history of North America and undoubtedly many other continental margins." 

    Follow Stephanie Pappas @sipappas. Follow LiveScience on Twitter @livescience, Facebook or Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Dust from Africa affects snowfall in California

    AP Photo / Jessie Creamean / NOAA

    This 2011 image provided by the National Oceanic and Atmospheric Administration shows a field survey site in California's Sierra Nevada mountains. A new study published Thursday found snowfall in the Sierras was influenced by dust and microbes from as far away as Africa.

    By Alicia Chang
    AP

    LOS ANGELES — One of the driest spots on Earth — the Sahara desert — is increasingly responsible for snow and rain half a world away in the western U.S., a new study released Thursday found.

    It's no secret that winds carrying dust, soot and even germs make transcontinental journeys through the upper atmosphere that can affect the weather thousands of miles away. Yet little is known about the impact of foreign pollutants on the West Coast, which relies on mountain snowmelt for its water needs.

    Previous studies hinted these jet-setting particles may retard rainfall in the Sierra Nevada mountains in Northern California by reducing the size of water droplets in clouds. But scientists who flew through storm clouds in an aircraft, measured rain and snow and analyzed satellite imagery found the opposite: Far-flung dust and germs can help stimulate precipitation.

    During the 2011 winter, a team from the University of California, San Diego and National Oceanic and Atmospheric Administration traced particles suspended in clouds over the Sierra to distant origins — from the skies over the arid Sahara that later mingled with other pollutants in China and Mongolia before crossing the Pacific.

    The days with the most particles in the clouds were also "days when we see the most snow on the ground," said study leader Kimberly Prather, an atmospheric chemistry professor at UC San Diego, whose study was published online Thursday in the journal Science.

    Scientists believe wafting dust, grit and microbes — including bacteria and viruses — can spur the formation of ice crystals in clouds that in turn can influence how much rain or snow falls.

    For years, governments and utilities in California and other Western states have used cloud seeding, in which a chemical vapor is sprayed into clouds, in a bid to increase rainfall.

    The new study shows how "Mother Nature has figured out how to give us more precipitation" and that may lead to changes in cloud-seeding efforts, which can be hit-or-miss, Prather said.

    David J. Smith at the NASA Kennedy Space Center said it was refreshing to see measurements from the ground, air and orbit to tackle how airborne particles affected Northern California snowfall.

    "Such a comprehensive approach is the only way to thoroughly examine global transport" of particles, Smith, who had no role in the research, said in an email.

    Online: Science 

  • Great white shark takes surprising trip to California

    NOAA photo library

    In case you were wondering: There are more shark attacks in U.S. waters than in any other region of the world.

    By Becky Oskin
    LiveScience

    A 15-foot-long (4.5 meters) great white shark unexpectedly veered toward California last week, an unusual winter trip never before tracked by researchers. Scientists monitor the sharks using satellite tags.

    The female great white shark, called Arden Grace, swam around Southern California's Channel Islands, visiting San Miguel Island and San Clemente Islands, beginning Feb. 14. Arden Grace, who has a satellite tracking tag on her dorsal fin, was likely hunting seals that live on the islands, said Michael Domeier, president of the Marine Conservation Science Institute, the Hawaii-based nonprofit research organization that tagged Arden Grace.

    "She may be cruising the California coast and eating California seals," he said.

    The trip is surprising for several reasons, Domeier said. First, Arden Grace is part of a population group based around Guadalupe Island in the Pacific Ocean, west of Baja California, Mexico. She is the first adult Guadalupe Island shark known to enter coastal California waters, Domeier said. In 2008, a great white shark from Northern California's Farallon Islands group was tracked to Guadalupe Islands, but the two populations have never interbred, Domeier said. [Image Gallery: Great White Sharks]

    Second, during this time of year, great white sharks from Mexico and California are usually found hundreds of miles offshore in the open ocean, in a region called the "White Shark Café," their shared offshore foraging area. "The timing is not at all what we would have expected from the more than 100 sharks we've tagged," Domeier said.

    Finally, Arden Grace's coastal exploration may be a sign she's not pregnant, though her size indicates she's a mature adult, Domeier said. Water is warmer in the shared feeding grounds, and some scientists think pregnant sharks prefer the balmy temperatures. "When mature females are pupping, they stay offshore in the middle of the ocean for 16 months," he said.

    Tracking from Arden Grace's tag dropped off Tuesday, because the shark is underwater, Domeier said. "She's got her head down and we're not sure where she's going to pop up," he said. "I suspect she's going to turn around pretty quickly and head offshore, but she may really surprise us and go up into Central California. "

    You can track the next stops on Arden Grace's journey via the MCSI's Expedition White Shark app or on its Facebook page.

    "There always seems to be a new chapter to great white sharks, and the more research we do, the more we learn about them. They continue to surprise us," Domeier said.

    Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. 

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Fireball over N. California causes stir

    Traveling at 33,000 mph, a massive meteor hit the Earth's atmosphere creating a giant shockwave that blew out windows of glass, injuring nearly 1,000 people and creating panic. On the same day, an asteroid half the size of a football field came within 17,000 miles from Earth. NBC's Tom Costello reports.

    By Gil Aegerter, NBC News

    A fireball streaking across the Northern California sky Friday night brought a flood of witness reports -- the same day that a meteor exploded over Russia and an asteroid made a near-Earth fly-by.

    The fireball was seen around 7:45 p.m., by witnesses as far north as Fairfield and as far south as Gilroy, NBCBayArea.com reported. It was also reportedly seen in Sacramento and Walnut Creek. NBC station KSBW of Monterey said the object was visible along California's Central Coast, too.

    NBCBayArea.com said Candice Guruwaiya gave this account on Facebook of seeing it in San Jose: "I was leaving Safeway on Branham and Snell when I saw it. ... It was a bright green when it first appeared, then it went to a bright yellow. It was awesome!"

    The fireball was seen about 24 hours after a meteor exploded over Russia's Chelyabinsk region and a 150-foot-wide asteroid came within 17,200 miles of Earth.

    An astronomer at the Chabot Space and Science Center in Oakland told NBCBayArea.com that Friday night's event wasn't related to the asteroid's passing:

    Gerald McKeegan, an astronomer at Chabot, said he did not see it, but based on accounts he thinks it was a "sporadic meteor," which can happen several times a day but  most of the time happens over the ocean, away from human eyes. Sporadic meteors bring as much as 15,000 tons of space debris to Earth each year, according to McKeegan. He explained that meteors, which are hunks of rock and metal from space that fall to Earth, burn up as they go through Earth's atmosphere, which is what apparently  caused tonight's bright flash of light.

    He said it was likely smaller than another meteor that landed in the Bay Area in October, which caused a loud sonic boom as it fell, breaking apart and spreading rocks, called meteorites, in the North Bay.

    More about the cosmic hits (and near-misses):

    Astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium, speaks to NBC's Lester Holt about the meteor and asteroid that approached Earth on Friday.