A solar-powered airplane finished crossing the United States on Saturday, landing in New York City after flying over the Statue of Liberty during its historic bid to circle the globe, the project team said. The spindly, single-seat experimental aircraft, dubbed Solar Impulse 2, arrived at New York's John F. Kennedy International Airport at about 4 a.m. local time after it took off about five hours beforehand at Lehigh Valley International Airport in Pennsylvania, the team reported on the airplane's website. Such a pleasure to land in New York! For the 14th time we celebrate sustainability," said the project's co-founder Andre Borschberg on Twitter after flying over the city and the Statue of Liberty during the 14th leg of the trip around the globe. The Swiss team flying the aircraft in a campaign to build support for clean energy technologies hopes eventually to complete its circumnavigation in Abu Dhabi, where the journey began in March 2015. The solar cr...
Initially measured by the US Geological Survey as magnitude 7.7, the quake is nowlisted by the USGS as magnitude 7.5. Even this revised assessment makes Monday's event a terribly powerful tremor. Around the world, only about 20 quakes each year, on average, measure greater than magnitude 7.0. But the origin of the shaking was more than 200km (125 miles) below the surface - much deeper than the magnitude 7.8 quake that brought widespread destruction to eastern Nepal in April. That event was only 8km deep and was followed by many aftershocks, including one in early May of magnitude 7.3. Similarly, the devastating tremor that killed tens of thousands in Kashmir almost exactly 10 years ago was magnitude 7.6 - and just 26km deep.
The much greater depth of Monday's quake appears to have
lessened the ground shaking that it produced, although its effects were felt over a wide area. The rupture dimensions will be very similar, but it's very far away from the Earth's surface, so there is strong shaking but it is much less severe than for a shallow earthquake," said Prof Martin Mai, an earthquake physicist from the King Abdullah University of Science and Technology in Saudi Arabia.Monday's tremor shares an overall cause with the Nepal earthquakes in April and May: the slow collision caused by India pushing north into the Eurasian continent. But they are not directly related.
"Those Nepal earthquakes are not directly linked to this; they did not set in train a chain of events that caused this earthquake," said geoscientist Prof David Rothery, from the Open University. "It's not part of an earthquake swarm." The Hindu Kush mountains sit on the corner of the Indian plate, rather than being at the front line of the continental collision, where the Himalayas are thrust upwards as India disappears beneath Eurasia at a rate of 40-50mm (2in) per year.
It is in this rugged region that the sideways slip between India and Afghanistan meets the head-on impact of the Himalayan fault line. There are many small, interacting faults and forces pushing in different directions."These earthquakes occurring at 200km are indicative of the processes of deformation that are occurring deep beneath the crust, as this piece of slab is being drawn down into the mantle underneath the Hindu Kush," said Simon Redfern, professor of mineral physics at the University of Cambridge.
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