September 9, 2014

Canadian Prime Minister Stephen Harper announced that a team of underwater archaeologists have discovered the wreck of one of two ships from the ill-fated Franklin expedition of 1845 in the waters of the Victoria Strait in the Arctic Ocean. Experts have searched for the wreckage for years. The discovery may help solve one of most enduring mysteries in World exploration–what became of English adventurer Sir John Franklin and his crew after they voyaged from England to find the fabled Northwest Passage, a northern water route across North America?

Routes traveled by explorers in search of a northern sea passage between Europe and Asia. The English explorer Henry Hudson, sailing for the Dutch East India Company, led an expedition in search of the passage in 1610 and 1611. Other expeditions included those by the British explorers Sir John Franklin (1845-1847) and Sir Robert McClure (1850-1854) and by the Norwegian explorer Roald Amundsen (1903-1906).

In the early 1800′s, the Royal Navy began sending expeditions to try to find a Northwest Passage in Arctic waters north of Canada. In 1845, Sir John Franklin, sent out to search for the passage, left England with 128 men aboard two ships, HMS Terror and HMS Erebus. It was the best-equipped expedition to enter the Arctic at that time. However, in September 1846, the ships were trapped by thick sea ice near King William Island. Franklin and several crewmen died there several months later. When no one returned from the voyage, Lady Franklin in 1848 sponsored the first of many expeditions to search for her husband. A full exploration of the Arctic resulted, but the ships and crew were never found. Later, explorers found evidence of Franklin’s party, including a written message left on King William Island in 1848 indicated that 105 surviving crew abandoned the ships that were hopelessly jammed in ice. Local Inuit people told the explorers stories that indicated some of the crew survived for years. However, none survived to return. The expedition’s fate became one of the great mysteries of the Age of Exploration in the 1800’s.

Since 2008, archaeologist with the Parks Canada service have conducted searches for the lost Franklin Expedition ships using sophisticated 3-dimensional sonar operated from a remote underwater vehicle to survey hundreds of square miles of seabed in the Arctic ocean. On September 7, the sonar detected the remnants of a large wooden ship on the Arctic seafloor. The detailed sonar images show the bow and stern of the ship and some of the deck structures are still intact, including the mainmast. The researchers believe that many items inside the ship are probably well preserved in the cold Arctic waters. However, they have not yet been able to determine if the wreckage is from the HMS Terror or the HMS Erebus.

The researchers stated that further investigation would be needed to identify the wreck and determine the state of preservation. However, no detailed plans have been announced.

September 2, 2014

Present-day Inuit people have virtually no genetic relationship with the earliest populations to inhabit the region, a surprising study of genetic material from prehistoric and modern Arctic peoples have shown. The analysis was conducted by scientists at the University of Copenhagen in Denmark. Archaeologists use the term Paleo-Eskimo to describe the earliest Arctic peoples who migrated into Arctic North America about 4,000 years ago. Many scientists assumed that these Paleo-Eskimos contributed to the ancestry of modern Inuit people as they were assimilated into Inuit society through intermarriage. However, genetic and archaeological evidence now strongly indicates that although Inuit ancestors and Pale-Eskimos shared the territory for a time, intermarriage and interbreeding was rare if it occurred at all.

The earliest Paleo-Eskimo people are called the Saqqaqs by archaeologists. They lived in small bands that hunted seal and caribou in the region beginning more than 4,000 years ago. The Tuniit people followed the Saqqaqs into Arctic North America in a series of migrations from across the Bering Strait. The Inuit refer to  the people who inhabited the Arctic before they arrived as the Tunitt. Archaeologists refer to the Tuniit as the Dorset culture. The Tuniit/Dorset people hunted seals, walruses, and narwhals. They spread across Canada to Greenland by about 500 B.C. But the Tuniit/Dorset people disappeared soon after another new culture called the Thule spread across the region about 1,000 years ago. The Thule people lived in villages. Whaling was the cornerstone of their culture. They also hunted on land with dog sleds and bow and arrow. By about 1700, the Thule culture had become the modern Inuit culture.

An Inuk fisher uses a pronged spear called a leister to catch his fish. Recent studies have revealed that modern Inuit are not related to the earliest inhabitants of Arctic North America. © Bryan & Cherry Alexander, Photo Researchers

In their study, the University of Copenhagen scientists collected bone, teeth, and hair samples from the preserved bodies of 169 ancient Paleo-Eskimo bodies from North America. The scientists isolated DNA from these samples and compared it to genomes sequenced from living Inuit and other Native American peoples. Native American groups are often reluctant to provide biological samples for genetic studies, but special tribal permission was given for this study.

The scientists found that the Paleo-Eskimo DNA samples were remarkably similar to each other yet genetically distinct from modern Inuit. The high degree of similarity in Paleo-Eskimo DNA suggests their populations were quite small. Over thousands of years, Paleo-Eskimo groups, each perhaps no more than 50 related individuals, spread out across the vast Arctic expanse. However, they apparently did not  interact with the Thule once they migrated into the region. The Paleo-Eskimos disappear from the archaeological record within a period of perhaps decades after the first Thule arrival. The abrupt disappearance of the Tuniit/Dorset people soon after this event remains mysterious. Archaeologists have not found any evidence of violent conflicts between Tuniit and the newly-arrived Thule. Some researchers suspect that the technologically advanced Thule may simply have out-competed the Paleo-Eskimo cultures in the rugged environment and pushed them towards extinction.

May 9, 2014

The biggest glacier (by size) in Europe is now draining into the Barents Sea at a rate 10 times as fast as it was just a few years ago, according to data collected by a new Earth-observation satellite. The glacier, the Austfonna icecap on Svalbard, had been relatively stable for some decades. (Icecaps are glaciers that cover an area of 19,300 square miles (50,000 square kilometers) or less. Larger glaciers are called ice sheets.) Svalbard is a group of islands in the Arctic Ocean, about midway between Norway and the North Pole. The Earth-observation satellite is the Sentinel-1A, an advanced radar satellite launched last month by the European Space Agency. Scientists with the Sentinel project described the change in the icecap’s speed as “extraordinary.” At this point, they are not certain whether the speed-up is the result of natural changes in the movement of the icecap or a sign of global warming in the Arctic.

The Austfonna icecap covers more than 3,000 square miles (8,000 square kilometers) of Nordaustlandet, the second-largest island in the Svalbard archipelago. Ice from the glacier drains into the sea mainly though a so-called outlet glacier along the southeastern coast of the island. An outlet glacier is a section of an icecap or ice sheet that moves faster than the ice around it.

The chief outlet glacier of the Austfonna icecap (shown in box) is flowing into the sea at least 10 times as fast as it was only a few years ago. (ESA/DLR/Gamma/University of Leeds/University of Edinburgh)

The melting of land-based glaciers is one of the two main causes of the 8-inch (210-millimeter) average rise in global sea levels that occurred between 1880 and 2009.  The other major cause is thermal expansion caused by the warming of the oceans (water expands as it warms). According to one expert involved with the project, icecaps and glaciers contain only 1 percent of the world’s ice. But they have contributed about 50 percent of modern sea-level rise due to ice melting. Glaciers flow slowly under the influence of gravity. If the amount of new snow that accummulates on the glacier is about the same as the amount of the glacier’s ice melting into the sea, the glacier is considered stable.

Additional World Book articles:

• Ice formation
• The Great Meltdown (a Special Report)

March 27, 2014

To scientists’ surprise, 70-million-year-old dinosaur fossils found some years ago in Alaska actually belonged to a previously unknown miniature cousin of Tyrannosaurus rex. This new species of pygmy dinosaur, Nanuqsaurus hoglundi, had a skull that was only 23 to 27 inches (60 to 70 centimeters) as an adult. The skull of an adult T. rex could be up to 60 inches (150 cm) long. (Note: The words pint-sized and pygmy here are relative. N. hoglundi was about the length of a polar bear, compared to which, students are pint-sized.)

The fossils—fragments of the top of the skull and jaw—were found in 2006 on Alaska’s North Slope, inland from Prudhoe Bay. The discoverers, who were involved in analyzing other fossils, shelved the fragments in a museum. When they recently examined the find, they discovered that the bones represented a new species of tyrannosaur. The tyrannosaurs, which lived during the late rank part of the Cretaceous Period, rank among the most frightening meat-eaters of their time. Tyrannosaurus rex, whose name means king of the tyrant lizards, is the most famous—but not the only—member of the genus.

Tyrannosaurs were fast, active carnivores. They roamed what are now western North America and east-central Asia. (c) Jan Sovak

A study of T. rex‘s mini cousin revealed that the part of N. hoglundi‘s brain devoted to smell was particularly enlarged. This suggests, the scientists said, that the dinosaur stalked its prey mainly by smell. A keen sense of smell would have been important in N. hoglundi‘s challenging environment. Although temperatures in what is now Alaska were much warmer 70 million years ago, the area still experienced long periods of darkness and challenging seasonal changes in the amount of available food. Scientists think the small size of this dinosaur predator was an adaption to its harsh environment. A smaller body is favored by natural selection because of the limited food sources available.

Additional articles in World Book:

• Tyrannosaurs rex: The Tyrant Still Reigns (a Special Report)
• What Has Caused Mass Extinctions? (a Special Report)

February 20, 2014

She was only one of the more than 2,500 snowy owls that left the Arctic for the United States and Canada this winter. But thanks to an encounter with a city bus and an SUV, she became a media star. On January 30, the owl, which had appeared in Washington, D.C., some days earlier, suffered a broken toe and a head injury in a traffic accident. Rushed to a city wildlife facility, she was treated successfully and moved to comfortably cold rooms for her recuperation. Apparently, she enjoyed the food—white mice—served at the facility. But as she improved, she became increasingly dissatisfied with her small accommodations. So earlier this week, her caretakers moved her to larger quarters at an undisclosed location. Bird experts there hope she will be healthy enough for release in spring, when snowy owls traditionally return to the Arctic.

Snowy owls are graceful birds of prey that usually live on the Arctic tundra in Canada, where they feed mainly on lemmings. The owls reach about 23 inches (58 centimeters) long and have mostly white plumage with brown markings. Adult females have more brown markings than the adult males.  In addition to lemmings, the owls may feed on mice, voles, ducks, and hares.

The call of the snowy owl features several rough notes and sounds somewhat like a dog’s bark. (Alan D. Carey, Photo Researchers)

Although snowy owls migrate south every winter, this year’s invasion has been one of the largest in memory, scientists said. Bird watchers working with eBird, an online citizen science project run by the Cornell University Lab of Ornithology and the National Audubon Society, have reported spotting the owls in 25 states and 7 Canadian territories. The project (at ebird.org) uses sightings collected by bird watchers in more than 115 countries to create maps showing where species can be found. Unlike most owls, snowy owls are active during the day, making them easier to observe. Usually, the younger birds make the trek south, chased out of their home range by older birds after fresh snow starts to fall. The lemmings take advantage of the cover to drop out of sight, significantly reducing the food available to the owls.

Additional World Book articles:

• Audubon, John James
• Bird
• Spotted owl

July 24, 2013

The release of large amounts of methane gas from thawing permafrost in the Arctic could have an enormous impact on the world economy, announce scientists in the journal Nature. The researchers estimated that the effects of the release of methane on climates worldwide–through rising sea levels, flooding, and damage to agriculture and human health–could amount to as much $60 trillion, roughly the size of the global economy in 2012.

Scientists have for years warned of the dangers posed by rising temperatures on permafrost. Large amounts of methane gas are concentrated in the frozen Arctic tundra. Methane commonly forms when plants decay in places where there is very little oxygen in the ground, such as tundra. When the ground thaws, the methane is released into the atmosphere.

Methane is released from Arctic tundra as the permafrost melts due to global warming. (© Scott T. Smith, Corbis)

Semi-solid gas hydrates are also concentrated under the world’s oceans. Diminishing ice cover in the Arctic Ocean, especially the East Siberian Sea, is resulting in warmer waters, allowing methane to leach out. Plumes of the gas more than a half mile in diameter have been detected rising from the sea.

The authors of the study estimated that the release of methane from the Arctic at the current rate will likely increase global temperatures by 3.6 Fahrenheit (2 Celsius) degrees in 15 to 35 years. Peter Wadhams of the University of Cambridge warned of the possibly catastrophic effect on global climate: “We are seeing increasing methane in the atmosphere . . . and the place where the increase is happening most is over the Arctic.” One of the authors of the study, Gail Whiteman of Erasmus University in the Netherlands, stated “That’s an economic time bomb that at this stage has not been recognized on the world stage. . . . We think it’s incredibly important for world leaders to really discuss what are the implications of this methane release and what could we indeed do about it to hopefully prevent the whole burst from happening.”

Additional World Book articles:

• Geology 2012 (a Back in Time article)
• Another Greenhouse Troublemaker (a special report)

February 19, 2013

Scientists announced this week that for the first time they had found living bacteria beneath a glacier in Antarctica. A team of scientists from the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD), funded by the U.S. National Science Foundation, made the find. The bacteria were discovered in Lake Whillans, which is about one-half mile (800 meters) below the West Antarctic Ice Sheet. The lake is about 5-feet (1.5-meters) deep, and scientists had to drill through the entire half mile of ice to take a sample of the lake water. After running a culture of the sample, they were able to see the bacteria under a microscope. The bacteria are members of a new ecosystem of living things that is able to survive with little light, at very cold temperatures, and under large amounts of pressure.

Lake Whillans sits at the upper tip of the Ross Ice Shelf in West Antarctica. (World Book map; map data © MapQuest.com, Inc.)

DNA testing is required for scientists to be able to identify the bacteria. Once identification has occurred, it might give scientists a better idea of what the bacteria use as food.

In addition to the excitement of finding life under Antarctic ice, scientists were also very interested in the bacteria because the conditions in Lake Whillan are not unlike some of the terrains found in outer space. For example, Jupiter’s moon, Europa, and Saturn’s moon, Enceladus, both have water that exists under ice. If the bacteria discovered under Antarctica is, for example, found to consume minerals from surrounding rock as food, a similar lifeform might be able to exist elsewhere in the solar system.

Additional World Book articles:

• Jupiter
• Europa
• Saturn
• Enceladus

September 24, 2012

Arctic sea ice melted to unprecedented levels in September, smashing all previous records. The sea ice reached its yearly minimum size on September 16, 2012, according to scientists with the National Snow and Ice Data Center (NSIDC). At that time, the sea ice covered 1.32 million square miles (3.41 million square kilometers), an area 18 percent smaller than ice cover at the last previous record, which was set in 2007. The NSIDC, located in Boulder, Colorado, is affiliated with NASA, the National Oceanic and Atmospheric Administration, and the University of Colorado.

Each year, Arctic sea ice grows and shrinks in area with the changing seasons. The sea ice reaches its largest area in March. It shrinks through the spring and summer, reaching its smallest size in September. It then grows through the fall and winter. This year, the ice shrank by 4.57 million square miles (11.83 million square kilometers) between March and September. That is the largest loss ever recorded, exceeding every other year by nearly 400,000 square miles (1 million square kilometers). The 2012 record was 49 percent smaller than the long-term average from 1979 to 2000, an area nearly twice the size of Alaska.  Arctic sea ice has deteriorated rapidly in recent years. In fact, all of the six lowest years for sea ice cover have occurred in the last six years.

Floating ice covers much of the Arctic Ocean’s surface. Most of the ice is sea ice (frozen seawater) that drifts with the currents. The rest is freshwater glacial ice, which breaks off from glaciers along the coasts of Arctic lands. Chunks of glacial ice form icebergs, seen in the distance in this photo. (© Corbis/SuperStock)

The 2012 record is all the more remarkable because summer weather in the Arctic was cooler than in 2007, the previous record-breaking year. In 2007, unusual warmth in the Arctic caused rapid melting. In contrast, the most important factor in 2012 was the thin, weakened ice itself. After many previous years of melting, much of the sea ice is new and thin. Such ice is more vulnerable to melting than older, thicker ice. In addition, a strong storm in early August helped to break up the weakened ice. Climate scientists warn that the Arctic Ocean could soon be entirely free of ice in the summers, possibly as early as 2015 to 2020.

Melting sea ice does not contribute to rises in sea level, because the ice is already floating on ocean water. However, scientists in 2012 also recorded unprecedented melting in Greenland, which does contribute to rising sea levels. NASA announced that 97 percent of the ice sheet in Greenland was melting during part of July. Scientists had never before measured such widespread melting. In the United States, July was the warmest month ever recorded, dating back to 1896.

Additional World Book articles:

• Global warming
• Greenhouse effect
• Kyoto Protocol
• Intergovernmental Panel on Climate Change
• The Great Meltdown (a Special Report)
• Global warming (2011) (a Back in Time article)
• Global warming (2010) (a Back in Time article)

August 30, 2012

The extent of the Arctic icecap fell to a record low on August 26, reported scientists with the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. The icecap was measured at 1.58 million square miles (4.1 million square kilometers), below the previous record of 1.61 million square miles (4.17 million square kilometers) set on Sept. 18, 2007, and the lowest level since satellite measurements began in 1979. NSIDC scientists noted that the icecap normally reaches it lowest point only in mid-September of each year, so there is a possibility that the sea ice may melt even more. The icecap grows larger during the cold Arctic winter, reaching about 6 million square miles (15.5 square kilometers).

The extent of Arctic sea ice fell on Aug. 26, 2012 (right), to 1.58 million square miles (4.1 million square kilometers), lower than the previous record low of 1.61 million square miles (4.17 million square kilometers) on Sept. 18, 2007. (National Snow and Ice Data Center)

NSIDC scientists also reported that the thickness of the icecap is diminishing. Submarine measurements indicate that the Arctic icecap has lost 40 percent of its thickness since the 1980′s. Between the loss of area and thickness, the summer ice volume in the Arctic in the 2000′s is only about 30 percent of its volume in the 1980′s. Of the finding, Peter Wadhams of Cambridge University in the United Kingdom said, “This means an inevitable death for the ice cover, because the summer retreat is now accelerated by the fact that the huge areas of open water already generated allow storms to generate big waves which break up the remaining ice and accelerate its melt.”

Scientists commenting on the findings linked the low ice levels to rising global temperatures. According to NSIDC scientist Ted Scambos, “We’re in a declining trend because the Earth is getting warmer. … It’s going to continue to be a series of shrinking ice extents year by year. … We’re not going back.” Climate scientists believe that the warming is mainly a result of human activity. The ice affects climate and weather conditions far beyond the North Pole.

Additional World Book articles:

• What We Know About Global Warming (A Special Report)
• The Great Meltdown (Special Report)
• Global warming (2007) (a Back in Time article)