Exploring the Yellowstone Supervolcano

Exploring the Yellowstone Supervolcano Theres a powerful and violent  menace lurking under northwestern Wyoming and southeastern Montana, one that has reshaped the landscape several times over the last several million years. Its called the Yellowstone Supervolcano and  the resulting geysers, bubbling mudpots, hot springs, and evidence of long-gone  volcanoes  make  Yellowstone National Park  a fascinating geologic wonderland. The official name for this region is the Yellowstone Caldera, and it spans an area about 72 by 55 kilometers (35 to 44 miles)  in the Rocky Mountains. The caldera has been  geologically active for  2.1 million years, periodically sending  lava  and  clouds of gas and dust into the atmosphere, and reshaping the landscape for hundreds of kilometers.   Yellowstone Caldera is among the  worlds largest such calderas. The caldera, its supervolcano, and the underlying magma chamber help geologists understand volcanism and is a prime place  to study first-hand the effects of hot-spot geology on the Earths surface. The History and Migration of the Yellowstone Caldera The Yellowstone Caldera is really the vent for a large plume of hot material that extends hundreds of kilometers down through Earths crust. The plume has persisted for at least 18 million years and is a region where molten rock from Earths mantle rises to the surface. The plume has remained relatively stable while the North American continent has passed over it. Geologists track  a series of calderas created by the plume. These calderas run from the east to northeast and follow the motion of the plate moves to the southwest. Yellowstone Park lies right in the middle of the modern caldera. The caldera experienced super-eruptions 2.1 and 1.3 million years ago, and then again about 630,000 years ago. Super-eruptions are massive ones, spreading clouds of ash and rock over thousands of square kilometers of the landscape. Compared to those, smaller eruptions and the hot-spot activity Yellowstone exhibits  today are relatively minor. The Yellowstone Caldera Magma Chamber The plume that feeds the Yellowstone Caldera moves through a magma chamber some 80 kilometers (47 miles) long and 20 km (12 miles) wide. It is filled with molten rock that, for the moment, lies fairly quietly below Earths surface, although from time to time, the movement of the lava inside the chamber triggers earthquakes. Heat from the plume creates  the geysers (which shoot superheated water into the air from underground), hot springs, and mudpots scattered throughout the region. Heat and pressure from the magma chamber is slowly increasing the height of the Yellowstone Plateau, which has been rising more rapidly in recent times. So far, however, there is no indication that a volcanic eruption is about to occur. Of more concern to scientists studying the region is the danger of hydrothermal explosions in between major super-eruptions. These are outbursts caused when underground systems of superheated water are disturbed by earthquakes. Even earthquakes at a great distance can affect the magma chamber.   Will Yellowstone Erupt Again? Sensational stories crop up every few years suggesting that Yellowstone is about to blow again. Based on detailed observations of the earthquakes that occur locally, geologists are sure that it will erupt again, but probably not  anytime soon. The region  has been fairly inactive for the past 70,000 years and the best guess is that  will remain quiet for thousands more.  But make no mistake about it, a Yellowstone super-eruption will happen again, and when it does, it will be a catastrophic mess. What Happens During a Super-Eruption? Within the park itself, lava flows from one or more volcanic sites would likely cover  much of the landscape, but the bigger worry is ash clouds blowing away from the site of the eruption. Wind would blow the ash as far as 800 kilometers (497 miles), eventually blanketing the mid-section of the U.S. with layers of ash and devastating the nations central breadbasket region. Other states would see a dusting of ash, depending on their proximity to the eruption. While its not likely that all life on earth would be destroyed, it would definitely be affected by the clouds of ash and the massive release of  greenhouse gases. On a planet where the climate is already altering rapidly, a additional discharge would likely change growing patterns, shorten growing seasons, and lead to fewer sources of food for all of Earths life. The U.S. Geological Survey maintains a close watch on the Yellowstone Caldera. Earthquakes, small hydrothermal events, even a slight change in the eruptions of Old Faithful (Yellowstones famous geyser), provide clues to changes deep underground. If magma starts to move in ways that indicate an eruption, the Yellowstone Volcano Observatory will be the first to alert surrounding populations.

Ethan Allen - American Revolution

Ethan Allen - American Revolution Birth: Ethan Allen was born at Litchfield, CT, on January 21, 1738, to Joseph and Mary Baker Allen. The eldest of eight children, Allen moved with his family to nearby Cornwall, CT shortly after his birth. Raised on the family farm, he saw his father become increasingly prosperous and serve as a town selectman. Educated locally, Allen furthered his studies under the tutelage of a minister in Salisbury, CT with the hopes of gaining admission to Yale College. Though possessing the intellect for higher education, he was prevented attending Yale when his father died in 1755. Rank Titles: During the French Indian War, Ethan Allen served as a private in the colonial ranks. After moving to Vermont, he was elected colonel commandant of the local militia, better known as the Green Mountain Boys. During the early months of the American Revolution, Allen held no official rank in the Continental Army. Upon his exchange and release by the British in 1778, Allen was given the rank of lieutenant colonel in the Continental Army and major general of militia. After returning to Vermont later that year, he was made a general in the Army of Vermont. Personal Life: While working as the part owner of an iron foundry in Salisbury, CT, Ethan Allen married Mary Brownson in 1762.  Though a largely unhappy union due to their increasingly conflicting personalities, the couple had five children (Loraine, Joseph, Lucy, Mary Ann, Pamela) before Marys death from consumption in 1783. A year later, Allen married Frances Fanny Buchanan. The union produced three children, Fanny, Hannibal, and Ethan. Fanny would survive her husband and lived until 1834. Peacetime: With the French Indian War well underway in 1757, Allen elected to join the militia and take part in an expedition to relieve the Siege of Fort William Henry. Marching north, the expedition soon learned that the Marquis de Montcalm had captured the fort.   Assessing the situation, Allens unit decided to return to Connecticut.   Returning to farming, Allen bought into an iron foundry in 1762. Making an effort to expand the business, Allen soon found himself in debt and sold off part of his farm. He also also sold part of his stake in the foundry to his brother Hemen.   The business continued to founder and in 1765 the brothers gave up their stake to their partners. The following years saw Allen and his family moved several times with stops in Northampton, MA, Salisbury, CT, and Sheffield, MA. Vermont: Moving north to the New Hampshire Grants (Vermont) in 1770 at the behest of several locals, Allen became embroiled in the controversy over which colony controlled the region. In this period, the territory of Vermont was claimed jointly by the colonies of New Hampshire and New York, and both issued competing land grants to settlers. As a holder of grants from New Hampshire, and wishing to associate Vermont with New England, Allen aided took in legal proceedings to defend their claims. When these went in New Yorks favor, he returned to Vermont and helped found the Green Mountain Boys at the Catamount Tavern. An anti-New York militia, the unit consisted of companies from several towns and sought to resist Albanys efforts to take control of the region. With Allen as its colonel commandant and several hundred in the ranks, the Green Mountain Boys effectively controlled Vermont between 1771 and 1775. With the beginning of the American Revolution in April 1775, an irregular Connecticut militia unit reached out to Allen for assistance in capturing the principle British base in the region, Fort Ticonderoga. Located at the south edge of Lake Champlain, the fort commanded the lake and the route to Canada. Agreeing to lead the mission, Allen began assembling his men and the necessary supplies. The day before their planned attack, they were interrupted by the arrival of Colonel Benedict Arnold who had been sent north to seize the fort by the Massachusetts Committee of Safety. Fort Ticonderoga Lake Champlain: Commissioned by the government of Massachusetts, Arnold claimed that he was to have overall command of the operation. Allen disagreed, and after the Green Mountain Boys threatened to return home, the two colonels decided to share command. On May 10, 1775, Allen and Arnolds men stormed Fort Ticonderoga, capturing its entire forty-eight man garrison. Moving up the lake, they captured Crown Point, Fort Ann, and Fort St. John in the weeks that followed. Canada Captivity: That summer, Allen and his chief lieutenant, Seth Warner, traveled south to Albany and received support for the formation of a Green Mountain Regiment. They returned north and Warner was given command of the regiment, while Allen was placed in charge of a small force of Indians and Canadians. On September 24, 1775, during an ill-advised attack on Montreal, Allen was captured by the British. Initially considered a traitor, Allen was shipped to England and imprisoned at Pendennis Castle in Cornwall. He remained a prisoner until being exchanged for Colonel Archibald Campbell in May 1778. Vermont Independence: Upon gaining his freedom, Allen opted to return to Vermont, which had declared itself an independent republic during his captivity. Settling near present-day Burlington, he remained active in politics and was named a general in the Army of Vermont. Later that year, he traveled south and asked the Continental Congress to recognize Vermonts status as an independent state. Unwilling to anger New York and New Hampshire, Congress declined to honor his request. For the remainder of the war, Allen worked with his brother Ira and other Vermonters to ensure that their claims to the land were upheld. This went as far as negotiating with the British between 1780 and 1783, for military protection and possible inclusion in the British Empire. For these actions, Allen was charged with treason, however since it was clear that his goal had been to force the Continental Congress into taking action on the Vermont issue the case was never pursued. After the war, Allen retired to his farm where he lived until his death in 1789.