Jeanna BrynerStaff WriterSPACE.com
The Red Planet had a fiery and watery past. New research reveals that beginning about 3.5 billion years ago, five episodes of violent volcanic activity spewed lava and hot water onto the Martian surface, sculpting the landscape into the dimpled world we see today.
Unlike on Earth, researchers say, the fashioning of the Martian surface has proceeded in spurts and stops. The rocky slabs that form Earth's outer surface steadily inch along to mold the mountains and valleys that shape our planet.
The results, presented last week at the Lunar and Planetary Science Conference at League City, Texas, depicted periods of volcanic activity alternating with relatively quiescent stints on Mars.
"We now have good evidence that volcanism on Mars and the release of water was not at the same level at all times, but it was episodic," said Gerhard Neukum of Freie University of Berlin and principal investigator for Mars Express, the spacecraft which returned the data behind this study.
Dating rocks
Neukum and his colleagues analyzed images from the High Resolution Stereo Camera (HRSC) on Mars Express. In order to estimate the ages of volcanic material on Mars, Neukum's team counted the number of small craters carved into the surface. The older the surface, the more craters it would have accumulated as meteorites of all sizes bombarded its surface.
"We can now determine the ages of large regions and resurfacing events on the planet," Neukum said. Resurfacing occurs when volcanic eruptions spread lava across the planet's surface.
From this technique, the team estimated five volcanic periods: ?3.5 billion years ago, 1.5 billion years ago, between 400 million and 800 million years ago, 200 million years ago and 100 million years ago. The dates of the earlier episodes, Neukum estimates, are correct to within 100 million to 200 million years and the later dates are correct to within 20 million to 30 million years.
The most recent activity on Olympus Mons, Mars's largest volcano, occurred at the summit around 150 million years ago with minor flows in some areas as recent as 2 million years ago. Neukum added that peaks in eruptions of the volcano match the dates his team found for global volcanic activity.
The team also investigated two large channels, Kasei Valles and Mangala Valles, revealing episodes of water flow that roughly match the times of high volcanic activity.
"So water flowed over the surface of Mars not just at the beginning but again and again throughout its history," Neukum told SPACE.com.
Martian plates
The bursts of volcanic activity could be explained by plate tectonics, or lack thereof. Whereas Earth is covered with a puzzle of rocky slabs called plates, Mars is a one-plate planet.
Over time, heat from Mars's interior builds up and can cause the crust to crack in some areas, releasing fiery magma (called lava when it reaches the surface). The internal heat generated by the volcanic activity also may have caused water to erupt from the interior, leading to wide-scale flash flooding.
These episodes might not be over.
"The interior of the planet is not cold yet, so this could happen again," Neukum said. But the chances of Mars Express or another orbiter spying such events are slim, because the eruptions happen much less frequently on Mars than on Earth, he added.
"So Mars is not dead," Neukum said.
Image Gallery: Wild Volcanoes
Martian Volcanoes May Not be Extinct
Image Gallery: Mars Express ? A Year of Discoveries
Original Story: Five Volcanic Episodes On Mars Identified by Scientists
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Showing posts with label five. Show all posts
Showing posts with label five. Show all posts
Tuesday, March 18, 2008
Sunday, March 16, 2008
After five years, the Iraq war is transforming the military
By Nancy A. Youssef, McClatchy Newspapers
WASHINGTON — When U.S. forces crossed the Kuwaiti border into Iraq in the pre-dawn hours of March 20, 2003 , the military set out to shock and awe the Middle East with the swiftest transformation the region had ever seen.
Five years and hundreds of billions of dollars later, it's the U.S. military that's been transformed. The efficient, tech-savvy Army , built, armed and trained to fight conventional wars against aggressor states, is now making deals with tribal sheiks and building its power on friendly conversations with civilians.
Instead of planning for quick, decisive battles against other nations, as it was five years ago, today's American military is planning for protracted, nuanced conflicts with terrorist groups, insurgents, guerrillas, militias and other shadowy forces that seldom stand and fight.
The staples of American military doctrine that have developed since the Civil War — artillery, armor, air power, speed and overwhelming force— are of limited use against enemies who blend into civilian populations.
Five years after the U.S.-led invasion of Iraq , the military is being reconfigured to fight insurgencies, but its evolution has been an unplanned, improvised affair, a series of course corrections in the midst of the wars in Iraq and Afghanistan . Some changes have been simply last-ditch efforts to stop the violence against Iraqis and U.S. troops, and some say the changes impair the military's ability to fight a conventional war against a "peer competitor."
Divisions are dispersed into what the military calls a more modular Army so smaller units can be moved throughout Iraq . The military has rolled out new vehicles to thwart high-powered explosives. It's set up new training centers and given captains and colonels far more leeway to lead at the local level, not simply follow a general's orders.
Pentagon leaders call this the military of the future.
"Clearly the training now is almost exclusively focused on COIN (counterinsurgency) because that's the fight we are in. And it will continue that way as long as the fight stays at the level that it is," said Adm. Michael Mullen , chairman of the Joint Chiefs of Staff, in an interview with McClatchy .
In the last five years, the military has gained "speed, agility (and) flexibility that . . . we didn't have as a much heavier force" a few years ago, Mullen said.
It's a big departure from the transformation that then-Secretary of Defense Donald H. Rumsfeld promised in the months leading up to the war. Under his plan, the Army would be smaller and rely more on precision air attacks and the latest technology.
Indeed, the war in Iraq was supposed to last a few weeks. The U.S. would dispatch the Iraqi military, overthrow Saddam Hussein's regime, install a new government led by Iraqi exiles and introduce freedom, democracy and a market economy.
Within days, however, the U.S. lost control. Looters took to the streets, and an insurgency took root. The U.S. installed an American occupation government and tried to secure a hostile nation rather than a grateful one.
Back then, there was little talk of counterinsurgency. But the new Army Field Manual puts counterinsurgency on a par with conventional war. "Winning battles and engagements is important but alone is not sufficient," it states. "Shaping the civil situation is just as important to success."
But while the Army has intellectually embraced counterinsurgency, it hasn't said how it will build a force that can fight both conventional wars and counterinsurgency campaigns. How should it train its soldiers? What kind of enemy will the U.S. face? So far, military leaders cannot agree on those fundamental questions.
By adopting a new mode of warfare, "the Army is a python that has just swallowed a pig," said a U.S. Army officer who spoke on the condition of anonymity in order to speak more candidly. "It's not clear to me it understands how hard the digestion process is going to be."
"The Army is going to have to build organizations optimized to do (post-combat) stability operations, and that's not what this Army wants to do," the officer added.
Lt. Col. John Nagl , who co-authored the U.S. military's 2006 counterinsurgency manual with Gen. David Petraeus , now the top American military commander in Iraq , questions whether the Army is serious about counterinsurgency.
"The real question is: How does the Army react to the (new field manual)? Can the Army transform itself to be as effective as possible in future battles, which are going to look a lot like Iraq and Afghanistan ?" Nagl said in an interview with McClatchy .
Some think that Iraq is a temporary problem and that the U.S. shouldn't engage in nation-building, as called for under counterinsurgency strategy.
Some think the Army isn't prepared for both kinds of war. Pete Geren , the secretary of the Army , testified on Capitol Hill last month that as the Army steps up counterinsurgency training, it's losing its conventional war skills.
"Our goal is full-spectrum readiness. And right now we're— we're not able to claim that," Geren said. "We are not able to properly organize, train and equip for the rest of the spectrum of operations."
Gen. George Casey , the Army chief of staff, has repeatedly warned that the Army is strained by having 160,000 troops in Iraq . Other Army leaders estimate that the U.S. must reduce its deployment to 12 combat brigades from the current 18 or find itself at the "breaking point."
The war in Iraq has required some soldiers to serve multiple tours of up to 15 months and to remain in uniform longer than they signed up for. Before the war started, soldiers generally served six-month tours in combat zones.
Mullen acknowledged the friction between counterinsurgency and conventional warfare.
"I think that (tension) will be constructive, and actually with what we learned through counterinsurgency, potentially very creative tension as we move to the next several years to get back to a broader spectrum of training."
The military's embrace of counterinsurgency came only in the last 18 months as soldiers noted measurable security improvements in Iraq . In the early years of the war, only a handful of military commanders spoke of the importance of economic development, respecting civilians and employing military might cautiously.
Back then, many ridiculed using "soft power" against what they considered a ruthless enemy. Soldiers said they were in Iraq to fight.
These days in Iraq , soldiers say they're likely to spend the rest of their careers in places such as Iraq , reaching out to civilians and fighting major battles only occasionally. Instead of generals giving orders from behind the front lines, captains and colonels will be forced to adapt as they maneuver through local, tribal politics. And many soldiers say those mid-level leaders will base their decisions on their experiences in Iraq .
Sgt. John Pierce Senkarik , 25, of 1st Brigade, 4th Stryker Brigade Combat Team, is serving in Diyala province, and could be one of them. Senkarik, of Pensacola, Fla. , comes from a family imbued with military history, and he once thought he'd fight the same kind of battles his forebears did. But since he signed up, he said, he's seen a transformation within the Army .
Senkarik, who's serving his second tour in Iraq , said he plans to stay in the military so the Army can capitalize on his experiences there.
"The Army is filled with junior leaders and middle-level leaders who have a vast amount of combat experience in counterinsurgency, in urban combat," he said. Mid-level officers will lead and be "responsible for the up-and-coming Army ."
( Steve Lannen of the Lexington Herald-Leader contributed from Diyala province, Iraq .)
WASHINGTON — When U.S. forces crossed the Kuwaiti border into Iraq in the pre-dawn hours of March 20, 2003 , the military set out to shock and awe the Middle East with the swiftest transformation the region had ever seen.
Five years and hundreds of billions of dollars later, it's the U.S. military that's been transformed. The efficient, tech-savvy Army , built, armed and trained to fight conventional wars against aggressor states, is now making deals with tribal sheiks and building its power on friendly conversations with civilians.
Instead of planning for quick, decisive battles against other nations, as it was five years ago, today's American military is planning for protracted, nuanced conflicts with terrorist groups, insurgents, guerrillas, militias and other shadowy forces that seldom stand and fight.
The staples of American military doctrine that have developed since the Civil War — artillery, armor, air power, speed and overwhelming force— are of limited use against enemies who blend into civilian populations.
Five years after the U.S.-led invasion of Iraq , the military is being reconfigured to fight insurgencies, but its evolution has been an unplanned, improvised affair, a series of course corrections in the midst of the wars in Iraq and Afghanistan . Some changes have been simply last-ditch efforts to stop the violence against Iraqis and U.S. troops, and some say the changes impair the military's ability to fight a conventional war against a "peer competitor."
Divisions are dispersed into what the military calls a more modular Army so smaller units can be moved throughout Iraq . The military has rolled out new vehicles to thwart high-powered explosives. It's set up new training centers and given captains and colonels far more leeway to lead at the local level, not simply follow a general's orders.
Pentagon leaders call this the military of the future.
"Clearly the training now is almost exclusively focused on COIN (counterinsurgency) because that's the fight we are in. And it will continue that way as long as the fight stays at the level that it is," said Adm. Michael Mullen , chairman of the Joint Chiefs of Staff, in an interview with McClatchy .
In the last five years, the military has gained "speed, agility (and) flexibility that . . . we didn't have as a much heavier force" a few years ago, Mullen said.
It's a big departure from the transformation that then-Secretary of Defense Donald H. Rumsfeld promised in the months leading up to the war. Under his plan, the Army would be smaller and rely more on precision air attacks and the latest technology.
Indeed, the war in Iraq was supposed to last a few weeks. The U.S. would dispatch the Iraqi military, overthrow Saddam Hussein's regime, install a new government led by Iraqi exiles and introduce freedom, democracy and a market economy.
Within days, however, the U.S. lost control. Looters took to the streets, and an insurgency took root. The U.S. installed an American occupation government and tried to secure a hostile nation rather than a grateful one.
Back then, there was little talk of counterinsurgency. But the new Army Field Manual puts counterinsurgency on a par with conventional war. "Winning battles and engagements is important but alone is not sufficient," it states. "Shaping the civil situation is just as important to success."
But while the Army has intellectually embraced counterinsurgency, it hasn't said how it will build a force that can fight both conventional wars and counterinsurgency campaigns. How should it train its soldiers? What kind of enemy will the U.S. face? So far, military leaders cannot agree on those fundamental questions.
By adopting a new mode of warfare, "the Army is a python that has just swallowed a pig," said a U.S. Army officer who spoke on the condition of anonymity in order to speak more candidly. "It's not clear to me it understands how hard the digestion process is going to be."
"The Army is going to have to build organizations optimized to do (post-combat) stability operations, and that's not what this Army wants to do," the officer added.
Lt. Col. John Nagl , who co-authored the U.S. military's 2006 counterinsurgency manual with Gen. David Petraeus , now the top American military commander in Iraq , questions whether the Army is serious about counterinsurgency.
"The real question is: How does the Army react to the (new field manual)? Can the Army transform itself to be as effective as possible in future battles, which are going to look a lot like Iraq and Afghanistan ?" Nagl said in an interview with McClatchy .
Some think that Iraq is a temporary problem and that the U.S. shouldn't engage in nation-building, as called for under counterinsurgency strategy.
Some think the Army isn't prepared for both kinds of war. Pete Geren , the secretary of the Army , testified on Capitol Hill last month that as the Army steps up counterinsurgency training, it's losing its conventional war skills.
"Our goal is full-spectrum readiness. And right now we're— we're not able to claim that," Geren said. "We are not able to properly organize, train and equip for the rest of the spectrum of operations."
Gen. George Casey , the Army chief of staff, has repeatedly warned that the Army is strained by having 160,000 troops in Iraq . Other Army leaders estimate that the U.S. must reduce its deployment to 12 combat brigades from the current 18 or find itself at the "breaking point."
The war in Iraq has required some soldiers to serve multiple tours of up to 15 months and to remain in uniform longer than they signed up for. Before the war started, soldiers generally served six-month tours in combat zones.
Mullen acknowledged the friction between counterinsurgency and conventional warfare.
"I think that (tension) will be constructive, and actually with what we learned through counterinsurgency, potentially very creative tension as we move to the next several years to get back to a broader spectrum of training."
The military's embrace of counterinsurgency came only in the last 18 months as soldiers noted measurable security improvements in Iraq . In the early years of the war, only a handful of military commanders spoke of the importance of economic development, respecting civilians and employing military might cautiously.
Back then, many ridiculed using "soft power" against what they considered a ruthless enemy. Soldiers said they were in Iraq to fight.
These days in Iraq , soldiers say they're likely to spend the rest of their careers in places such as Iraq , reaching out to civilians and fighting major battles only occasionally. Instead of generals giving orders from behind the front lines, captains and colonels will be forced to adapt as they maneuver through local, tribal politics. And many soldiers say those mid-level leaders will base their decisions on their experiences in Iraq .
Sgt. John Pierce Senkarik , 25, of 1st Brigade, 4th Stryker Brigade Combat Team, is serving in Diyala province, and could be one of them. Senkarik, of Pensacola, Fla. , comes from a family imbued with military history, and he once thought he'd fight the same kind of battles his forebears did. But since he signed up, he said, he's seen a transformation within the Army .
Senkarik, who's serving his second tour in Iraq , said he plans to stay in the military so the Army can capitalize on his experiences there.
"The Army is filled with junior leaders and middle-level leaders who have a vast amount of combat experience in counterinsurgency, in urban combat," he said. Mid-level officers will lead and be "responsible for the up-and-coming Army ."
( Steve Lannen of the Lexington Herald-Leader contributed from Diyala province, Iraq .)
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