Earthweek: A Diary of the Planet (April 25, 2014)

Impact Odds
A group aiming for early detection of asteroids that threaten to collide with Earth says our planet experienced 26 powerful asteroid explosions in the atmosphere from 2000 to 2013.  The nonprofit B612 Foundation says data collected by the Comprehensive Nuclear Test Ban Treaty Organization, which uncovered the blasts, demonstrates that the chance of an asteroid inflicting catastrophic damage is higher than previously estimated.  Former astronaut Ed Lu, who now heads the California-based foundation, told reporters that an asteroid as small as 130 feet across has the potential to level a city.  While the 2013 blast above the Russian city of Chelyabinsk got global news coverage, the B612 Foundation says asteroid impacts with a force greater than 20 kilotons also occurred above the Indonesian island of Sulawesi in 2009, over the Southern Ocean in 2004 and above the Mediterranean in 2002.  The group is currently constructing an asteroid-hunting, infrared space telescope called Sentinel.  It's likely to track more than 200,000 asteroids once launched in 2018.
March Contrasts
The U.S. environmental agency NOAA says March 2014 was the fourth-hottest on record for the planet, even though America notably bucked that trend.  The agency calculated that the overall global temperature for the month was 1.3 degrees Fahrenheit above the 20th-century average.  But the continental United States was almost a full degree cooler than normal, making it the country's 43rd coolest March on record.  The Eastern European nation of Slovakia had its hottest March on record while South Korea experienced its second-warmest.  Northern Siberia came in at 9-degrees warmer than normal for the month.
Ebola Variant Strain
Scientists have found that a new strain of the Ebola virus is responsible for the latest outbreak in West Africa, where more than 140 people of the nearly 230 believed infected have died from the disease.  In a report published in the New England Journal of Medicine, researchers say that the virus may not even be new to the area, and could have been circulating undetected for some time.  It suggests that there was probably "a single introduction of the virus into the human population" prior to December 2013, adding, "the virus was (probably) transmitted for months before the outbreak became apparent."  It's now thought that "patient zero" was a 2-year-old girl who died in December.  A variant of the most virulent Zaire strain has been identified as the cause of the girl's death in Guinea, before Ebola spread elsewhere across that country and into neighboring Liberia.  The study said fruit bats were likely carriers of the virus.
Java Rumblings 
Increased seismic activity from within Indonesia's Mount Merapi was punctuated before dawn on April 20 by a blast that showered ash over areas within about 7 miles of the volcano's summit.  While a glow was observed at the top of Merapi around the time of the blast, vulcanologists said no new lava was observed flowing from the volcano.  That means the mountain was probably not entering a new eruptive phase.  An eruption of Merapi in 2010 released poisonous gases and blanketed the region in ash, killing more than 300 people.
*       Explosions from Guatemala's Fuego (Fire) volcano intensified, prompting officials to warn some nearby residents that lava flows could soon threaten their homes.
Tropical Cyclone
Tropical Cyclone Jack formed briefly over the open waters of the eastern Indian Ocean.  The storm was initially a threat only to shipping lanes in the region, but its remnants later forced a temporary halt to the aerial search for missing Malaysian Airlines Flight MH370.
Earthquakes
A wide area of southwestern and central Mexico was rocked on the morning of April 18 by a 7.2 magnitude quake, centered near the Pacific resort of Acapulco.  At least 127 homes were damaged near the epicenter in the state of Guerrero.
*      Earth movements were also felt in the northeastern Caribbean, the northwestern Philippines, eastern Papua New Guinea, northwestern Vancouver Island and central Oklahoma.
Stork Revival
Two wild storks recently observed nesting in eastern England could be the first pair to breed in Britain for nearly 600 years.  The BBC reports the birds are nesting on a chimney at Norfolk's Thrigby Hall Wildlife Gardens and are engaging in mating rituals.  The last wild stork documented to be nesting in Britain was at St. Giles' Cathedral in Edinburgh, back in 1416.  Conservation efforts elsewhere in Europe during recent years have resulted in a modest return of the birds, which now appear to have ventured across the North Sea to raise a proper English brood.  The storks nest in North Africa, across Europe and into Asia.  They are known around the world as symbols of fertility.