Posts Tagged ‘oceans’
Time-Lapse ISS Video of Earth Lets You Orbit in HD
The movie starts in the Pacific Ocean and flies over North and South America before sunrise over Antarctica. The neuronal network of nighttime cities is marvelous to behold — not to mention the lightning storms off the southern coast of Mexico and into the Pacific.
It takes roughly a minute to fly from Vancouver Island to the southern portion of Chile. A real latitudinal arc on the ISS takes much longer, of course, but I like this fast view because it’s somewhat humbling — this planet is not really that big. Plus, you get an appreciation for just how much if it is oceans.
Raw data was downloaded from the Gateway To Astronaut Photography of Earth, a Johnson Space Center project. to see even more astronaut images, which should keep you sated until the ISS gets a sometime next year.
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Pluto May Be Hiding Oceans Underneath Its Frozen Exterior
Space Boat: A Nautical Mission to an Alien Sea
In May, the TiME project received a $3-million development contract from NASA. If the space agency green-lights the mission, the capsule will lift off in 2016. By 2023, TiME will be about 800 million miles away in Titan’s north-polar region, home to its biggest lakes and seas. The capsule will take photographs, collect meteorological data, measure depth, and analyze samples. TiME will have no means of propulsion once it is on Titan, so it will float, carried by breezes across the sea’s surface. Then, by the mid-2020s, it will enter a decade-long winter of darkness as the moon’s orbit takes it to the dark side of Saturn, away from the sun and communication. It won’t have a line of sight to Earth to beam back more data until 2035.
Methane clouds drift in Titan’s smoggy orange skies, sometimes releasing hydrocarbon raindrops, which replenish the seas and sculpt the landscape the way water does on Earth. But Titan’s seas probably don’t contain life. “Life as we know it requires liquid water, and Titan’s surface is far too cold for this,” says Ralph Lorenz, a physicist at Johns Hopkins University who is working on TiME. “Its seas can tell us about how molecules organize and evolve, and how life may arise more generally.” TiME’s principal investigator, planetary geologist Ellen Stofan, wonders about the waves: “Are there hazes, sea spray? Is the liquid clear or cloudy? Is there scum floating on the surface? With Titan’s seas, there are endless questions.”
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Splash Landing on Titan's Sea
DROP IN
After a seven-year journey, including gravitational slingshots around Earth and Jupiter, the Titan Mare Explorer (TiME) passes through Titan’s thick nitrogen and methane atmosphere, protected by its heat shield.
DRIFT DOWN
At an altitude of about 100 miles, TiME deploys its parachute. During the remainder of its roughly two-hour descent, the probe’s camera snaps pictures while a thermometer and barometer record meteorological data.
FLOAT AROUND
After landing in the ethane and methane sea Ligeia Mare, TiME’s mass spectrometer collects a sample to analyze its chemical composition, while its sonar measures the sea’s depth. Without its own means of propulsion, the capsule will bob along in the gentle wind and currents. It might even experience alien rains or wash up on an extraterrestrial beach.
Cosmic Contenders
Next year, NASA will give full funding to one of three missions: a Mars probe to study how the planet formed, a “comet hopper” that will repeatedly land on a near-Earth comet, or a capsule to float on a sea on Titan, one of Saturn’s 53 known moons.
The Jet Propulsion Laboratory’s Geophysical Monitoring Station would study Mars’s interior structure and composition to better understand its geological history.
The Comet Hopper, conceived at NASA’s Goddard Space Flight Center, would land several times on a comet, studying how the icy body evolves as it warms up while approaching the sun.
Climate Scientists Request Protection From Somali Pirates
Climate scientists are asking the Australian and U.S. navies to help ward off pirates so they can deploy robotic instruments in the western Indian Ocean, reports the Independent.
Researchers at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) want to deploy about 20 monitoring instruments north of Mauritius, a tiny island off the east coast of Madagascar. The devices are programmed to submerge and resurface, recording ocean heat and salinity patterns and transmitting data to satellites. The data will help improve climate models and forecasts for monsoons and floods in Australia and southeast Asia, the scientists say.
The project is part of the international Argo collaboration, in which more than 3,000 robotic monitoring systems are tracking ocean heat and salinity.
But piracy in the area has made it too dangerous for research vessels to bring the instruments out to sea,
“I know there's a report of at least one ship that hired an armed escort – that's pretty extreme when you're talking about climate change,” she said.
Then again, .
The western Indian Ocean is still a pirate hot spot, the Independent notes. In the first half of his year, 163 of 266 attacks were carried out by Somali pirates in the Indian Ocean. The U.S. military has been guarding merchant vessels from attack, but piracy is still on the rise — there have been 100 more attacks this year than over the same period last year. The Navy has even experimented with communities to develop new anti-pirate strategies, but it proved too popular and the Navy had to back off.
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Study: Rising Global Temperatures Spur Steepest Sea Level Rise In 2,100 Years
Reconstructing sea level history for the first time
The findings will help improve climate models and scientists’ understanding of future sea level changes due to human-caused climate change. Until now, studies of sea level rise have been largely limited to satellite data, comprising a couple of decades, and tide-gauge records, comprising about 300 years.
Sea level increase is one of the most threatening aspects of climate change. Increases in global average temperatures will cause ice sheets to melt, gradually increasing the average height of the oceans and inundating coastal areas across the globe.
Sea levels were stable from at least 100 BC to 950 AD, according to Benjamin Horton, a professor of earth and environmental sciences at the University of Pennsylvania who co-authored the study, published in the Proceedings of the National Academy of Sciences. The levels rose a bit for the next 400 years, during a warm period known as the Medieval Climate Anomaly, and then they were stable again throughout the Little Ice Age, which lasted until the late 1800s. Since the onset of the industrial age, sea levels have risen by more than 2 millimeters per year — by far the steepest increase in the past 2,100 years.
“For the last 1,000 years, whenever temperature has changed, sea level has changed,” Horton said in an interview. “It’s a huge body of evidence to say that in the 21st century, with temperatures shown to be rising, that sea levels will rise. That’s a great worry that comes out of this study.”
To reach this conclusion, Horton and colleagues at the University of Pennsylvania, Penn State, Yale University and institutions in Germany and Finland studied core samples taken from the salt marshes of North Carolina’s Outer Banks.
Salt marshes contain plants and bacteria that respond in measurable ways to changes in salinity, so their location at various sediment layers can provide clues about sea levels. Horton and colleagues studied microfossils called foraminifera that were preserved in the sediment cores. The sediment samples’ ages were determined with radiocarbon dating, Horton said.
“As you go deeper and deeper, you go back through time,” he said.
The area has been mostly undisturbed by humans — there are no ditches, buried pipelines or cables to interrupt the natural sediment deposits, Horton said — and it offers a uniquely consistent rate of subsidence, or sediment deposition, as a remnant of the last ice age. Without this gradual sinking of the land, there would be no new sediment, Horton said. The researchers had to account for the deposition rate to ensure their data was accurate, he said. Previous research determined the natural subsidence rates for the areas in question, Sand Point and Tump Point, N.C.
Although humans may not have disrupted the land, hurricanes have certainly taken their toll on the Carolinas several times in the past two millennia. Powerful winds and waves could have shifted the sediment layers, interfering with history. To account for this, the team drilled samples at sites that did not face the ocean, Horton said. He added that hurricanes would leave an obvious imprint in the core samples, with large grains of sand rudely embedded in the soft deposits.
The researchers drilled core samples several feet deep, and stopped at a depth equivalent to 2,000 years of sediment deposition. This is a much shorter time frame than the typical core samples taken from Arctic ice sheets, but it’s easy to correlate to known historical temperatures, Horton said.
After accounting for naturally occurring subsidence, Horton et. al found that sea levels rose an average of 0.6 millimeters a year from about 800 AD-1080 AD, for the following 400 years.
“If you look at our sea level record, the first acceleration is around 1000 AD. What we would expect is that temperatures would be warming, and we know they are, during the medieval warm period. You can assume that the oceans expanded and the ice sheets melted. Then you have a period of stable sea level, which coincided with the Little Ice Age — the oceans may have slightly contracted, so the sea level corresponds to that,” Horton said.
After 1850, temperatures began to rise, and so, too, did the seas, Horton said. Incidentally, Penn State climatologist Michael Mann, who helped create the famous “hockey stick” graph of temperature trends over the past 1,000 years, is a co-author on this study.
In some ways, the correlation should not be surprising, Horton said.
“It’s evidence to support the obvious. The basic laws of physics say if you increase temperature, ice will melt,” Horton said. “But what we show is how sensitive sea level is to changes in temperature. The medieval warm period was a very subtle change, but it results in a response in sea level. It indicates that they are intrinsically linked, and it’s a very sensitive and instantaneous response.”
Despite this strong correlation, the study is mum on future sea level projections. The data will serve to improve the models that will predict those increases, Horton said.
The research was funded by the and published in this week's issue of PNAS.
Google Earth Goes Under the Sea
Seeing the sea floor is just the beginning of the fun. Along the way, Google Earth points out eruptions, sea animals and other scientific points of interest from Hawaii to New York, all in nicely clear high resolution. (You can take a virtual tour through some highlights if the entire ocean world seems overwhelming.) This imagery represents nearly two decades of collected data from research ships that travelled about three million nautical miles and a partnership with scientists at Columbia University's Lamont-Doherty Earth Observatory.
It's a pretty amazing tool--finally, there's a reason to venture off the green-brown mass on which we live and venture beneath the blue. At least on Google Maps. We'd understand if you wanted to sit inside today and enjoy your air conditioning. for a glimpse of the underwater experience.
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To Harvest Natural Gas From the Ocean, Shell Is Building the World’s Largest Man-Made Floating Object
The floating liquified natural gas facility will dwarf the biggest warships, weighing in at 600,000 metric tons. By contrast, the U.S.’ next-generation Ford-class supercarrier will displace 101,000 metric tons of water. Shell says its ship will be able to withstand a category 5 typhoon.
In some ways, it’s more of a mini-island than a ship, designed to be moored in the same spot off the northwest coast of Australia for 25 years. The facility will be one-third of a mile long — longer than five football fields laid end-to-end — and will contain 260,000 metric tons of steel, about five times the amount used to build the Sydney Harbour Bridge.
The ship will chill the natural gas to -260° F to reduce its volume by 600 times, enabling it to be shipped to customers throughout Asia, according to Shell.
Shell did not disclose the cost of building the project, but said it would be built at Samsung Heavy Industries’ Geoje Island shipyards in South Korea, one of the few shipyards in the world capable of building such a monstrous vessel.
Once it is built, the Prelude will be towed to its station about 300 miles northeast of Broome, Australia, and hooked up to the massive Prelude natural gas field, which Shell discovered in 2007. Shell anticipates production to start in 2017. The facility will tap into about 3 trillion cubic feet of natural gas, the company said.
Without an oceangoing facility, it would be impossible to harvest natural gas that far from land, Shell said. The Prelude will be the first facility of its kind, but not the last — the design can accommodate a wide range of gas fields, said Malcolm Brinded, executive director for Shell’s Upstream International, in a . So someday, massive floating gas factories could be deployed in various oceans throughout the world.
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