younger dryas flood

} } return no_error; } } if (input.type == 'text') { } else if (input.type == 'textarea'){ Please deactivate your ad blocker in order to see our subscription offer. true : no_error = false; ... More 600 cubic miles of water was released when that ice dam failed. } Trees were knocked down and burned over hundreds of square kilometres. callback(); The prevailing hypothesis, proposed by Broecker et al. In contrast to the Younger Dryas Meteor Impact theory, an unsettled scientific study many proponents of Atlantis lately use to explain how Atlantis was lost, there is a more verifiable scientific explanation behind the flood that is said to have destroyed (the Cyclades Plateau) Plato's Atlantis. new_tooltip.elem = elem; }); The Younger Dryas was a period that lasted from 12 800–11 600 years ago. tooltip.className = '_error-inner _no_arrow'; Giant ripples averaging 24 feet high in Washington Scablands created by Missoula Flood (also called Spokane Flood) were up to 360 feet between crests. From around 16,000 years ago, the world began to emerge from the deep freeze of the last ice age. To his colleagues, Bretz’s idea was dismissed as religious heresy with no geologists taking serious notice of his claims. if (tooltips[i].elem === elem) { The source of this flood was apparently the glacial Lake Agassiz, located along the southern margin of the Laurentide Ice Sheet, which at its maximum 21,000 years ago was 6,500 to 9,800 feet (2,000 to 3,000 meters) thick and covered much of North America, from the Arctic Ocean south to Seattle and New York. }; if (callback) { "); "); return el.name == 'email' || el.getAttribute('required') !== null; if (!value.match(/^\d\d\d\d-\d\d-\d\d$/)) { Thousands of square miles of vegetation were completely washed away as well as intense amounts of soil and sediment. This mini ice age, known as the Younger Dryas, lasted around 1,000 years, and it's considered a crucial period for humanity because it was around that time agriculture and the first Neolithic civilisations arose - potentially in response to the new colder climates.The period has also been linked to the extinction of the woolly mammoth.. var remove_tooltips = function() { } The ice core record at Dome C shows that climate changes in Antarctica were out-of-phase with those in the Northern Hemisphere (EPICA Community Members 2004). validate_field(this, true); }); } if (!no_error && e) { } return match ? Apparently around the younger dryas period they now suspect multiple pieces of an asteroid hit the earth in multiple places at the same time. } no_error = false; } } else if (input.tagName == 'SELECT') { The debate on what caused the prehistoric ice sheet melt has raged since the early 1900’s. This places the melt of the Cordilleran Ice-Sheet to a time earlier than the Younger Dryas. }; However, new evidence has revealed that the collapse of prehistoric glaciers occurred in as little as 4000 years. From 19 000 years, the Earth began to warm. if (validate_form()) { e.preventDefault(); The Younger Dryas occurred 11,100 to 10,000 radiocarbon years ago. Now the evidence of a planet-shaking flood during this time is mounting. }; match[2] : null; tooltips[i].tip.parentNode.removeChild(tooltips[i].tip); The Big Freeze was not a glacial period, which are colloquially often called ice ages — it was a cold time in the relatively warm spans between glacial periods. Originally the ice-sheets were thought to have melted over tens of thousands of years in a very slow process. new_tooltip.no_arrow = true; "Prior to the flood, meltwater is thought to have drained into the Gulf of Mexico, down the Mississippi River. } if (_removed) return; var err = form_to_submit.querySelector('._form_error'); wrapper.className = '_form-inner'; The Younger Dryas flood theory emerges. if (!no_error) { err.parentNode.removeChild(err) : false;

for (var i = 0; i < allInputs.length; i++) { tooltip ? "In contrast, when the meltwater enters the ocean from the Gulf of St. Lawrence, ocean currents cause it to be confined largely to the sub-tropical North Atlantic about 3,000 kilometers (1,800 miles) south of the Greenland and Labrador Seas," Condron said. The global climate would then have beco… var setCookie = function(name, value) { Today, we are blessed with technology that allows swift recording of geological land features. Giant boulder in Eastern Washington carried by ice during the Missoula Flood. var wrapper = document.createElement('div'); Many are still observable today. It is generally believed that the Younger Dryas period coincides with the end of the last ice age. for (var i = 0; i < elem.options.length; i++) { _load_script("//d3rxaij56vjege.cloudfront.net/form-serialize/0.3/serialize.min.js", function() { Save my name, email, and website in this browser for the next time I comment. "); Younger Dryas flood events: A case study from the middle Warta River valley (Central Poland) return new_tooltip; if (window._old_serialize) window.serialize = window._old_serialize; var resize_tooltip = function(tooltip) { if (no_error && elem.name == 'email') { Most of North America and Western Europe were covered in a glacial ice sheet. } var validate_form = function(e) { new_tooltip.tip = tooltip; addEvent(window, 'scroll', resize_tooltips); (_above|_below) ?/g, '') + ' _below'; The impact energy has been … "); e.preventDefault(); The Younger Dryas impact hypothesis or Clovis comet hypothesis posits that fragments of a large, disintegrating asteroid or comet struck North America, South America, Europe, and western Asia sometime between 12,800 to 11,700 years ago. document.querySelector('#_form_1_submit').disabled = true; Scientific discussion continues over what caused ice sheets of North America to disappear. We attribute to this flood a boulder terrace near Fort McMurray with calibrated radiocarbon dates of over 11,500years ago. These were carved out by Missoula Flood waters. Initially, it was thought it disappeared over tens of thousands of years in a slow gradual melt. tooltip = create_tooltip(elem, "Enter a valid date. Your email address will not be published. Geologists classify this period as the Younger Dryas. } remove_tooltip(elem) : false; head.appendChild(script); Tunguska meteoroid impact, a fraction of the Younger Dryas event. }; elem.value = elem.value.trim(); The waters from Lake Agassiz were originally suggested more than two decades ago to have poured through the Great Lakes and St. Lawrence Valley. Sea levels were much lower and the continents were unlike they are today. Studies now reveal that Western Canada was ice-free some 14 000 years ago. The approximate position of the ice sheet is shown (in white) just before the onset of the Younger Dryas. if (fieldVal) { "It is only by simulating the circulation of the ocean at 10 to 15 times the resolution previously achieved by modelers that we have been able to accurately capture the pathway that the meltwater would have taken in the ocean," Condron told OurAmazingPlanet. Wallace S. Broecker GEOLOGY A s Earth’s surface warmed at the end of the last glacial period, the Laurentide ice sheet that covered much of North America retreated and a vast melt water lake— Lake Agassiz—formed in the area of today’s Great Lakes. } else { Your email address will not be published. Data was slow, as it was incredibly hard to observe large geological land features without an expensive plane. A giant flood of Arctic meltwater may have triggered an ancient 1,200-year-long chill nicknamed the "Big Freeze," the last major cold age on Earth, a new study finds. A large flood into the Arctic Ocean at the start of the Younger Dryas leads us to reject the widespread view that Agassiz overflow at this time was solely eastward into the North Atlantic Ocean. }; for (var i = 0; i < elems.length; i++) { }; var regexStr = '[\?&]' + name + '=([^&#]*)'; } But others have held out, suggesting that volcanic eruptions or, what seems to be the leading favorite, some sort of massive freshwater flood temporarily disrupted climate cycles based out of the North Atlantic. var needs_validate = function(el) { var rect = tooltip.elem.getBoundingClientRect(); validate_field(elem) ? For most of the 20th-century geologists believed the transition out of the ice age was a gradual process. var selected = true; err ? (Image credit: Alan Condron and Peter Winsor, PNAS), a cosmic impact might have set off this Big Freeze, 7 Ways the Earth Changes in the Blink of an Eye, Scientists find deep-sea bacteria that are invisible to the human immune system, Rarest great ape on Earth could soon go extinct, Creepy sculpture with human faces is even older than experts thought. He inspired a generation of researchers to have another look at evidence left by end of the ice age. var form_submit = function(e) { oldFunc.apply(this, arguments); It’s hard to picture that the earth was in a full glacial ice age just 12 000 years ago. addEvent(input, 'input', function() { var div = document.createElement('div'); These findings hint that shifts in the flow of water in the Arctic could dramatically alter today's climate. During the Younger Dryas period there was an unexplained extinction of 75% of the North American megafauna. This deluge would have diluted the circulation of saltwater in the North Atlantic, disrupting the ocean "conveyer belt. inner.innerHTML = text; Others have postulated that the Younger Dryas event was caused by a meteor impact. if (!no_error) { for (var i = 0, len = allInputs.length; i < len; i++) { It was a period where 6 billion cubic meters of ice needed to be distributed across the planet. Please refresh the page and try again. document.cookie = name + '=' + value + '; expires=' + now + ';path=/'; div.className = '_error-html'; The North American ice sheets of prehistoric earth. } else { Was the Younger Dryas Triggered by a Flood? Do the geological scars across North America suggest a Younger Dryas flood? if (!elems[i].checked) { Many scientists have suggested – with evidence – that the Younger Dryas was triggered by a meteorite impact. var radios = form_to_submit.elements[el.name]; } The flood’s trail of destruction can still be seen throughout the geology of North America. Photo: Tom Foster. The Younger Dryas Period. } return; elems[i].className = elems[i].className + ' _has_error'; if (elem.options[i].selected && !elem.options[i].value) { } Around 10,800 ± 200 radiocarbon years ago, this overflow ceased . The story in Antarctica is somewhat different, however. It is now clear that the ice was completely gone in as little as a few thousand years. } J Harlen Bretz was awarded the Penrose Medal in 1979 for outstanding contributions to the geological society. } err.innerHTML = message; } else { window._load_script = function(url, callback) { var elem = allInputs[i]; validate_field(this, true); elem.className = elem.className + ' _has_error'; After the dam broke, the water rapidly flowed into the ocean via a different river drainage system." A great blanket of ice called the Cordilleran Ice Sheet covered most of Canadian North America, dipping down into parts of the U.S. As the ice melted, it formed lakes like Lake Missoula where the water was held in by a 2,000-foot wall of ice. tooltips = []; addEvent(form_to_submit, 'submit', form_submit); To see which flooded waterway might best explain the plummeting temperatures seen during the Younger Dryas, a group of scientists developed computer models that studied the impact meltwater from the two outlets had on the conveyer belt of currents known as the Atlantic Meridional Overturning Circulation. addEvent(radios[i], 'click', function() { var tooltip = document.createElement('div'), arrow = document.createElement('div'), inner = document.createElement('div'), new_tooltip = {}; THE YOUNGER-DRYAS IMPACT AND THE WORLDWIDE FLOOD The YD ImpactThe YD event is an episode marked by abrupt increases in snowfall and dramatic changes to flora, fauna, climate, and the oceans (Firestone et.al., 2007). It doesn’t explain how the much, much larger Laurentide Ice sheet vanished in a geological blink of an eye. In this article, we’ll outline new scientific discussions on earth’s prehistory and the Younger Dryas flood. At the height of this earth period, all of Canada, Northern US, Western Europe, the Himalayas, the Rockies, and the Andes were all covered in an ice sheet. for (var i = 0; i < radios.length; i++) { if (! var now = new Date(); } else if (value === undefined || value === null || value === '') { if (elem.type != 'checkbox') elem.className = elem.className.replace(/ ?_has_error ?/g, ''); addEvent(window, 'resize', resize_tooltips); (function(el) { addEvent(input, 'blur', function() { if (elem.tagName.toLowerCase() !== "select") { A large flood into the Arctic Ocean at the start of the Younger Dryas leads us to reject the widespread view that Agassiz overflow at this time was solely eastward into the North Atlantic Ocean. } else { var allInputs = form_to_submit.querySelectorAll('input, select, textarea'), tooltips = [], submitted = false;

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