USEPA Photo by Eric Vance
This week, our top Earth snapshots include an amazing Alaskan flyover, the Space Station's peaceful view of Russia and Eastern Europe -- and a red tide that's causing havoc in Florida. The EPA maintains these controlled growth chambers (above) in Corvallis, Ore. They enable researchers to study the effects of air pollution, heavy metals and toxic substances on plant life.PHOTOS: Massive Mayfly Invasion Marauds Midwest
This image of Alaskan forest land was shot from a Piper Cherokee aircraft by NASA scientists. They're conducting an aerial survey of 174,000 square miles of forests in the Alaskan interior, which are difficult to reach on the ground.BLOG: A Huge Alaska Quake Could Devastate California
From the International Space Station, an astronaut captured this view of the southern Baltic sea. Russia, Poland and Lithuania are in the foreground, while Norway, Denmark and Sweden are seen in the distance.PHOTOS: Costa Concordia's Final Journey
USDA photo by David Kosling
California is suffering through a severe drought. This image, taken back in February, shows a dried-up riverbed along Highway 99 near Bakersfield.NEWS: Southwest Groundwater Disappearing at 'Shocking' Rate
Kim Parsons/NOAA Fisheries
A group of killer whales, also known as orcas, are seen swimming here in a tight pattern. NOAA scientists recently published a study of killer whale genetics, in which they reported that the creatures form distinct sub-populations that don't have much cross-breeding.VIDEO: Whales Get Sunburned, Too
Typhoon Rammasun, AKA Glenda, battered the Philippines in mid-July. The storm is seen here in a satellite photo.BLOG: How Do Summer Superstorms Form?
Florida Keys National Marine Sanctuary Staff; Florida Keys National Marine Sanctuary
A sergeant major fish and an angelfish swim in a reef in the Florida Keys National Marine Sanctuary. These fragile underwater habitats are threatened by rising levels of carbon dioxide in the water, due to climate change.NEWS: When Fish Go Deeper They Glow Brighter
A red tide off the coast of Florida has killed thousands of fish along with sea turtles and crabs,reports the AP
. The algal bloom is caused by a marine organism,
which is naturally occuring buttoxic to humans and wildlife
.PHOTOS: Earth Shots: Must-See Planet Pics (July 18)
Northern California is still recovering from the effects of a 6.0 quake on Sunday, which injured more than 100 people and may have caused as much as $1 billion in damage. But it could be just the foreshadowing of a much larger quake that researchers expect to occur in the region sometime in the next couple of decades.
A 1999 USGS study of northern California’s earthquake risk predicted that there is a 62 percent probability of a quake that will be 6.7 or greater by 2032. There are seven known major faults in the region, and possibly others that have not yet been discovered.
The scariest prospect: There’s a 1-in-10 chance of a catastrophic quake of between 7.0 and 7.5 on either the San Andreas or San Gregorio faults, and about a 1-in-20 chance that the San Andreas could generate a quake the size of the infamous 1906 event that nearly destroyed San Francisco.
The Sunday quake, which destroyed more than 30 buildings in Napa, provided a glimpse of the sort of carnage that a much larger quake might cause. Emir Macari, a professor of seismic safety at California State University-Sacaramento and a member of the state’s Seismic Safety Commission, told Sfgate.com that despite earthquake-proofing building codes, there still are tens of thousands of older non-reinforced masonry structures in the state.
“It most definitely is a wake-up call … to realize what the danger of this is, and what the risks are,” Macari said.
Even more alarmingly, the LA Times reports, the quake still caused some buildings that had undergone seismic retrofits to collapse, exposing the limitations of the protective technology.
A 7.0 quake, which would be roughly 10 times as powerful as the one Sunday, would likely cause far more failures.
Photo: Damage to a building in Napa, Calif., from the 6.0 earthquake. Credit: James Gunn, via Wikimedia Commons