Geologic time and relative dating lab
Methane, a highly flammable gas, gets trapped under the ice of some Arctic lakes in winter. If a hole is punched through the ice, the escaping gas can be lit into a fireball. September 8, , was an exciting date for Katey Walter Anthony. Few people visit this remote stretch of wilderness. It is covered in tundra and scraggly spruce trees. Thousands of lakes dot the region.
Relative age dating of geologic features answers
Methane, a highly flammable gas, gets trapped under the ice of some Arctic lakes in winter. If a hole is punched through the ice, the escaping gas can be lit into a fireball. September 8, , was an exciting date for Katey Walter Anthony. Few people visit this remote stretch of wilderness. It is covered in tundra and scraggly spruce trees. Thousands of lakes dot the region. But Walter Anthony quickly realized that this lake was strange. As her boat glided across it, she came to a place where the water seemed to be boiling.
But it roiled and fizzed. Bubbles of all sizes streamed up, popping at the surface. One bubble, as large as a softball, gave off a loud bloonk as it ruptured. The bubbles covered a swath of the lake larger than a football field. And they rose with such force that they slowly pushed her boat to the side. Walter Anthony leaned over the edge of the boat and collected some bubbles in a bottle.
Then she struck a match and opened the bottle to release the gas she had just collected. The gas caught fire! The yellow-tipped flame that danced over the bottle confirmed her suspicion. It showed that the lake was gurgling out a flammable gas, called methane. Each molecule CH 4 contains one atom of carbon bonded to four atoms of hydrogen. As a potent greenhouse gas, methane can absorb radiation from the sun, warming the atmosphere.
Methane, along with carbon dioxide, is a major source of global warming. Walter Anthony works at the University of Alaska in Fairbanks. To date, she has studied more than of them in the Arctic. Many give off methane. But Lake Esieh was different. She could hear a deep-throated gurgling as bubbles shoved their way up, violently, through the mud at the bottom of the lake. It was coming from deep below her boat.
Scientists believe that the Arctic could release large amounts of methane over the next years. The gas is naturally released as frozen soil, called permafrost, warms up and thaws. And some scientists worry that this methane will cause the world to warm more quickly than they had predicted. Walter Anthony has spent nearly 20 years trying to understand this threat. She is trying to measure how much methane is coming out of warming Arctic lakes.
And to her, Lake Esieh could be a warning. If other lakes respond the same way, the Arctic could be poised to burble out far more methane than anyone had expected. Permafrost covers 22 million square kilometers 8. This frozen soil is rich in organic matter — the remains of plants that lived hundreds or thousands of years ago. These dead plants froze before they could fully decay. But as that permafrost now thaws, single-celled microbes have begun dining on those plant remains.
They break down the dead stuff into mush, like kitchen scraps in a compost heap. Along the way, the microbes exhale methane and another carbon-based gas, carbon dioxide CO 2. Scientists have long known that melting permafrost would release these gases. What has not been clear is how much might come out and how quickly. People are especially concerned about methane. Over a period of years, it absorbs more than 20 times as much heat, gram for gram, as carbon dioxide does.
Walter Anthony has been figuring out just how much methane Arctic lakes are spewing. She started in , while she was working toward her PhD at the University of Alaska. Back then, she was spending much of her time in Siberia, in northeast Russia. Thawing permafrost can make the ground sag. Walter Anthony saw tiny bubbles of methane bubbling up as she paddled her boat across one of these Siberian lakes, called Shuchi.
But she could never anticipate where a bubble would emerge. This Sergey Zimov suggested that she try a new approach: Wait until winter freezes the lake over. The ice might trap methane bubbles, showing her where the gas was accumulating. In October , she donned a down jacket and headed out into the cold. She shoveled snow off a strip of lake ice, then poured water onto it.
This smoothed the ice so that she could see through it into the lake below. The white gas bubbles stood out against the dark background of the water below. For the first time, she realized that most of the bubbles were coming up in very specific places — and always the same places. Now she knew where those places were. She used a crowbar to chip holes in the ice. She had the help of a large fellow named Dmitri Draluk, who also worked as a local firefighter, preacher and bodybuilder.
She and Draluk inserted bottles, with upside down funnels, to collect the gas that was bubbling up. They kept the bubble traps in place even after the ice melted. After a year of catching bubbles, Walter Anthony could finally calculate how much methane had been bubbling up. Scientists had thought that most methane seeped up without forming bubbles. They believed the bubbles held only a little of the gas. And because scientists had missed those bubbles, they had underestimated how much methane the lakes were belching.
Thousands of thermokarst lakes dot the surfaces of Siberia, Alaska and Canada. Once a thermokarst lake has formed, the permafrost beneath can now thaw much more quickly. This is partly because the darker lake absorbs more sunlight than will frozen soil. Walter Anthony and her collaborators estimate that this boost in thawing could cause Arctic permafrost to release twice as much carbon by as people had predicted.
That, in turn, could cause more warming, more permafrost thawing — and then even more greenhouse gases to be released. Scientists call this vicious cycle a positive feedback. That may not sound like much. But it could make a big difference if people still hope to keep the Earth from warming more than another 1. He is a climate scientist at the University of New Hampshire in Durham.
It would mean people will have to reduce their emissions of greenhouse gases by even more. And Walter Anthony has only just started studying that lake. Two members of her team first spotted Lake Esieh from an airplane in April During several days of flying, they passed over hundreds of lakes. Most were still covered in winter ice. But Melanie Engram and Allen Bondurant noticed that one lake had two large dark spots free of ice.
Walter Anthony first visited the lake five months later. With a graduate student, her husband and their two young sons, she climbed into a boat and motored four hours up a river to reach the lake. Once there, it was easy to find the methane hot spots. Not exactly frightening — but strange. Walter Anthony and her team returned to Lake Esieh in May They camped on a hillside overlooking one of the bubbling spots.
Sharp boated around the lake using sonar, or pulses of sound, to map its bottom. Most of the lake was only about a meter 3 feet deep. But beneath each hot spot, she found a deep crater in the lake bottom. One of them plunged to a depth of 15 meters 49 feet. Walter Anthony, Sharp and several others returned to the lake again in August The hillside where they had camped three months earlier was crumbling. Muddy cracks had opened in the ground. Blocks of soil up to 1.
He has visited plenty of Arctic lakes with Walter Anthony over the years. He was shocked to find that this one was giving off methane times faster than most others he had seen. Carbon builds up in plants while they are alive.
Procedure: Today we will be interpreting geologic history from geologic cross- sections. Geologic history is a series of events that resulted in the. Geology 2 – Physical Geology Lab. Lab #8 – Geologic Time - Relative Dating. Student Outcomes: Become familiar with the principles used to determine the.
This question. Walk around the tin cans layer of , h, and how are the grand canyon. Activity christine mclelland Continued W. How are deposited horizontally or event is the geological time as faults and evidence for mudcracks, we presented a body of sediments.
General Geology Lab 7: To use relative dating techniques to interpret geological cross sections. Today we will be interpreting geologic history from geologic cross-sections.
General Geology Lab #7: Geologic Time & Relative Dating
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Relative age dating of geologic features answers
By Douglas Preston. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. Sixty hours later, the asteroid hit. The air in front was compressed and violently heated, and it blasted a hole through the atmosphere, generating a supersonic shock wave. In that moment, the Cretaceous period ended and the Paleogene period began. The result was a slow-motion, second-by-second false-color video of the event. Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere. Picture the splash of a pebble falling into pond water, but on a planetary scale.
Teaching about Earth's history is a challenge for all teachers.
- Голос его прозвучал резко, но спокойно. - Тебе удалось стереть электронную почту Хейла. - Нет, - сконфуженно ответила. - Ты нашла ключ.
Strange lake belches flammable gas in the high Arctic
Беккер почувствовал тошноту. Это какая-то глупая шутка. Он не находил слов. - Ты знаешь ее фамилию. Двухцветный задумался и развел руками. - Каким рейсом она летит. - Она сказала, колымагой. - Колымагой. - Ну да, это ночной рейс в выходные - Севилья, Мадрид, Ла-Гуардиа. Его так все называют.
The Day the Dinosaurs Died
- Из всех различий между ураном и плутонием наверняка есть такое, что выражается простым числом. Это наша главная цель. Простое число. Джабба посмотрел на таблицу, что стояла на мониторе, и всплеснул руками. - Здесь около сотни пунктов. Мы не можем вычесть их все одно из другого. - Многие пункты даны не в числовой форме, - подбодрила людей Сьюзан.
Здесь не было ни души, если не считать уборщицы, драившей пол. На противоположной стороне зала служащая закрывала билетную кассу компании Иберия эйр-лайнз. Беккеру это показалось дурным предзнаменованием. Он подбежал к кассе. - El vuelo a los Estados Unidos. Стоявшая за стойкой симпатичная андалузка посмотрела на него и ответила с извиняющейся улыбкой: - Acaba de salir.
ГЛАВА 11 Испания. Я отправил Дэвида в Испанию. Слова коммандера словно обожгли Сьюзан. - Дэвид в Испании? - Она не могла поверить услышанному. - Вы отправили его в Испанию? - В ее голосе послышались сердитые нотки.
Беккер оказался на прямом отрезке, когда вдруг улочка начала подниматься вверх, становясь все круче и круче. Он почувствовал боль в ногах и сбавил скорость. Дальше бежать было некуда. Как трасса, на продолжение которой не хватило денег, улочка вдруг оборвалась. Перед ним была высокая стена, деревянная скамья и больше. Он посмотрел вверх, на крышу трехэтажного дома, развернулся и бросился назад, но почти тут же остановился.
В некотором отдалении от него возникла фигура человека, приближавшегося медленно и неотвратимо.
Это была предсмертная мольба. Энсей Танкадо незаметно кивнул, словно говоря:. И тут же весь обмяк. - Боже всемилостивый, - прошептал Джабба. Камера вдруг повернулась к укрытию Халохота.Relative Dating - Example 2