Daily Archives: September 12, 2022

Director Erin Sikorsky | Sea Level Rise & Military Bases | 8 Sept 2022

Sep 12, 2022

Erin Sikorsky, Director of the Center for Climate and Security, speaks to the Weather Channel about climate risks at US military bases.

Antarctica : What happens if the ‘Doomsday’ Glacier collapses?

Just Have a Think– Mar 15, 2020

Antarctica is home to some of the world’s largest ice sheets and glaciers. They existed in a stable equilibrium of ebb and flow for millions of years until global warming started to melt them faster than the snow falls could replenish their ice. Now a new US / UK research collaboration has discovered that the rate of melt is even worse than scientists feared. What’s driving this latest acceleration, and can we slow it down? Video Transcripts available at our website http://www.justhaveathink.com

Antarctica’s melting ‘Doomsday glacier’ could raise sea levels by 10 feet, scientists say

Science and tech news– Sep 7, 2022

Antarctica’s melting ‘Doomsday glacier’ could raise sea levels by 10 feet, scientists say. One of Antarctica’s most important glaciers is holding on “by its fingernails” as warming temperatures around the globe threaten to cause further deterioration, which could then destabilize the glaciers in the entire region. The Thwaites glacier, located in the Amundsen Sea in western Antarctica, is among the fastest-changing glaciers in the region, according to scientists. Along with Pine Island, also located in the Amundsen Sea, the two structures are responsible for the largest contribution of sea level rise out of Antarctica. To stay up to date with latest top stories, make sure to subscribe to this YouTube channel by clicking the button above this video! Now, scientists are finding that the Thwaites glacier, also known as the “Doomsday glacier,” is melting faster than previously thought as warm and dense deep water delivers heat to the present-day ice-shelf cavity and melts its ice shelves from below, according to a study published in Nature Geoscience on Monday.

Jan 6th Committee Members Prepare To Work Until The Bitter End

MSNBC– Sep 12, 2022

Washington Post congressional investigations reporter Jackie Alemany and writer-at-large for The Bulwark Tim Miller discuss the January 6th committee resuming public hearings this month as they look to wrap up their investigation of the Capitol attack.

Why You Should Be Worried About This Glacier

VICE News– Aug 31, 2022

Known as the ‘Hollywood Glacier,’ Europe’s largest ice cap has been the picturesque and otherworldly scene of movies and TV shows for decades. But the real drama lies underneath; Vatnajökull glacier sits across some of the most active volcanoes in Iceland. Embedded with a team of drone pilots and scientists, VICE World News investigates if the country’s melting glaciers could lead to catastrophic volcanic eruptions which could impact our entire planet. Directing Producer: Louise McLoughlin DOP: Zuka George Shooting Producer: Alice Stevens Editor: Oli Mason

Antarctica’s ‘doomsday glacier’ holding on by its fingernails, scientists say

Science and tech news– Sep 6, 2022

Antarctica’s ‘doomsday glacier’ holding on by its fingernails, scientists say. Antarctica’s so-called “doomsday glacier” – nicknamed because of its high risk of collapse and threat to global sea level – has the potential to rapidly retreat in the coming years, scientists say, amplifying concerns over the extreme sea level rise that would accompany its potential demise. The Thwaites Glacier , capable of raising sea level by 60cm, is eroding along its underwater base as the planet warms. To stay up to date with latest top stories, make sure to subscribe to this YouTube channel by clicking the button above this video! In a study published today in Nature Geoscience , scientists mapped the glacier’s historical retreat, hoping to learn from its past what the glacier will likely do in the future. They found that at some point in the past two centuries, the base of the glacier dislodged from the seabed and retreated at a rate of 2.1km per year. That’s twice the rate that scientists have observed in the past decade or so.

‘Doomsday Glacier’ is teetering even closer to disaster than scientists thought, new seafloor map shows | Live Science

By Harry Baker
published 4 days ago

Researchers say the icy mass is “holding on by its fingernails.”

Underwater robots that peered under Antarctica’s Thwaites Glacier, nicknamed the “Doomsday Glacier,” saw that its doom may come sooner than expected with an extreme spike in ice loss. A detailed map of the seafloor surrounding the icy behemoth has revealed that the glacier underwent periods of rapid retreat within the last few centuries, which could be triggered again through melt driven by climate change.

Thwaites Glacier is a massive chunk of ice — around the same size as the state of Florida in the U.S. or the entirety of the United Kingdom — that is slowly melting into the ocean off West Antarctica. The glacier gets its ominous nickname because of the “spine-chilling” implications of its total liquidation, which could raise global sea levels between 3 and 10 feet (0.9 and 3 meters), researchers said in a statement. Due to climate change, the enormous frozen mass is retreating twice as fast as it was 30 years ago and is losing around 50 billion tons (45 billion metric tons) of ice annually, according to the International Thwaites Glacier Collaboration.

The Thwaites Glacier extends well below the ocean’s surface and is held in place by jagged points on the seafloor that slow the glacier’s slide into the water. Sections of seafloor that grab hold of a glacier’s underbelly are known as “grounding points,” and play a key role in how quickly a glacier can retreat.

…(read more)

Understanding and predicting atmospheric rivers | Here & Now

Dismantle the Commonwealth: Queen Elizabeth’s Death Prompts Reckoning with Colonial Past in Africa

Sep 12, 2022

The death of Queen Elizabeth II has focused global attention on the British royal family and renewed criticism of the monarchy both inside the U.K. and abroad, especially among peoples colonized by Britain. “There’s a degree of psychosis that you can go to another people’s land, colonize them, and then expect them to honor you at the same time,” says Kenyan American author Mukoma Wa Ngugi, who teaches literature at Cornell University and whose own family was deeply impacted by the bloody British suppression of the Mau Mau revolution. He says that with Queen Elizabeth’s death, there needs to be a “dismantling” of the Commonwealth and a real reckoning with colonial abuses. We also speak with Harvard historian Caroline Elkins, a leading scholar of British colonialism, who says that while it’s unclear how much Queen Elizabeth personally knew about concentration camps, torture and other abuses in Kenya during her early reign, the monarchy must reckon with that legacy. “Serious crimes happened on the queen’s imperial watch. In fact, her picture hung in every detention camp in Kenya as detainees were beaten in order to exact their loyalty to the British crown,” says Elkins.

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The world as they knew it: New Beinecke exhibition charts rise of maps | YaleNews

By Mike Cummings,  September 1, 2022

After mapmaker Judah Ben Zara was banished from Spain in 1492, when Ferdinand and Isabella expelled their kingdom’s Jewish population, the exiled cartographer continued plying his craft in the Middle East. His only surviving maps — two made in Egypt and one in Galilee — are among the few existing examples created outside of Europe during this period.

One of those maps, a portolan chart of the Mediterranean Sea he produced more than a decade later in Tsefat — a city located in present day northern Israel — is on view as part of “The World in Maps 1400–1600,”

a new exhibition at Yale’s Beinecke Rare Book & Manuscript Library that presents a selection of the most impressive and historically important maps in the library’s collection from the late Medieval and Early Modern periods.

“What’s fascinating is that Ben Zara’s maps look just like those being produced in Spain and Italy at the time,” said Ray Clemens, curator of early books and manuscripts, who organized the exhibit with Kristen Herdman, a Ph.D. candidate in the medieval studies program. “He took his mapmaking knowledge with him from Spain, but he used different materials than European-based mapmakers.”

Specifically, peptide mass fingerprinting, an analytical technique used to identify proteins, revealed that the 1505 map is made on goatskin, Clemens said, while contemporary European maps in the library’s collection were produced on either sheepskin or calfskin.

“He lived where there were no sheep or calves,” he said, “so he’s improvising.”

Yale boasts one of the most significant map collections in North America, including the continent’s largest single assemblage of portolans — navigation charts that seafarers used to find ports. Ten of the Beinecke Library’s portolans, which comprise the exhibit’s centerpiece, are displayed in the two flat cases on either side of the building’s ground floor. In addition, a selection of maps from Asia is displayed in a curved case on the library’s mezzanine. On the mezzanine’s opposite side, a second curved case contains examples of forged maps, including the notorious Vinland Map, once considered the earliest depiction of the New World. Eighteen smaller cases lining the east and west sides of the mezzanine display materials concerned with various historical, cultural, or technological aspects of mapmaking.

Not technically maps, portolans are nautical charts that offer few geographic details about the interiors of the land masses they depict. Like other examples from the period on display, Ben Zara’s depicts the orbis terrarum — the circle of land surrounding the Mediterranean — identifying scores of major and minor ports from Spain to Greece to Egypt and present-day Morocco. (Red identifies major ports, black denotes minor ones.) Red and black lines, called rhumb lines, crisscross the chart and helped sailors to determine courses from one port to another. The charts often vividly mark shoals and other treacherous features near the coastlines.

Even though Ben Zara and his contemporaries lacked the benefit of satellite imagery or even hot air balloons to get a bird’s eye view of the terrain, their renderings of the Mediterranean coastline are impressively accurate. They often added whimsical, artistic flourishes. For instance, palm trees, billowing tents, and an ostrich dot the North African coast on Ben Zara’s portolan. He painted the Red Sea’s waters red — a visual cliché on portolan charts. And like other portolans from the period, Ben Zara’s map shows a land bridge near the sea’s northern shores representing the location where the Israelites escaped Egypt in the biblical Exodus account.

“Of course, in the biblical story, the sea closes after the Israelites cross the parted waters, drowning the pharaoh’s troops,” Clemens said. “It’s representation on this and portolan charts shows how they served historical as well as geographical documents.”

In the exhibition, Ben Zara’s Tsefat chart is paired with a facsimile of his first known map — presently housed at the Vatican Library — which he made in Cairo in 1497. These maps share the flat case to the left of the library’s security desk with the oldest map in the library’s collection — a portolan chart made by Genoese mapmaker Franciscus Becharius in 1403.

The case also contains the oldest known portolan from Portugal, which was completed by mapmaker Jorge de Aguiar in 1492. At that point in history, the Portuguese had successfully explored the west coast of Africa for European interests and Aguiar shared what they had learned of the African coastline in two insets on the chart. Columbus brought a similar map on his first voyage to the Americas, according to the exhibit label.

The flat case to the right of the security desk features portolans made after European cartographers began contemplating the New World in their work. A portolan of the Atlantic dated to after 1637 outlines the routes used in the slave trade between Africa and Brazil. An illustration of Elmina Castle, an early European trade settlement in present-day Ghana that became a base for slave traders, features prominently on the Gold Coast of Africa.

A portolan chart of the Atlantic that outlines the slave trade. The Castle of Elmina, a major stop on the slave trade located in present-day Ghana, is featured prominently under a Dutch flag, which dates the map to after 1637 when the Dutch took control of the region.

A curved case on the north end of the mezzanine offers a sense of how Asian cultures viewed their place in the world. Manuscripts maps of Asia are extremely difficult to find outside of China, Japan, and Korea, but the Beinecke Library has a small collection of printed maps made from earlier originals, Clemens said. A large political map of Korea at the case’s center is an 18th-century reproduction of a map likely made during the Joseon Dynasty in the 16th-century.

“It’s important because it shows Korea’s eight provinces, but it’s also just a gorgeous map,” Clemens said.

A display case along the east wall contains two copies of Da sphaera (“On the sphere”), a 13th-century

text by astronomer Johannes de Sacro Bosco that shows, contrary to contemporary myth, that medieval people conceived of the world as an orb.

One of the copies, produced in the 15th century, includes an illustration of an astronomical model with Earth at the center, the sun at the periphery, and depictions of the moon in its various phases at it circles the globe. The second copy, created between 1526 and 1527, includes a foldout map of the world. It is a version of a T-O map, which were common in medieval Europe. These maps were simple diagrams consisting of a “T,” which typically divides the world into Asia, Europe and Africa, enclosed in an “O” that represents the waters surrounding land masses. While used for instruction, T-O maps were not meant to reflect the shape of the world, Clemens explained.

A case displaying Arabic world maps includes a copy of a 17th-century copy of map of the world from “A Book of Marvels and Things Created” by 13th-century cosmographer Zakariyya’ al-Qazwini. Mecca sits at the map’s center, the rest of the world spreading out in a circle from it. The Red Sea is a rectangular blue mass. The Mediterranean is oblong shaped at the map’s top-left.

A treatise Geoffrey Chaucer penned circa 1450 on how to use an astrolabe is included in a case containing manuscripts about the astronomical instrument that sailors used to determine latitude. He dedicated the work to his son.

At its conclusion, the exhibit turns its gaze to the heavens. The final small case on the building’s west side holds several copies of Galileo’s first printed images of the moon. The famed astronomer’s detailed sketches of the cratered lunar landscape — the first ever created with the benefit of a telescope — introduced many Europeans to the dark side of the moon. Before Galileo’s discoveries, many people believed that the moon generated its own light, Clemens said.

A black and white image of the Earth taken in 1966 by Lunar Orbiter 1, the first U.S. spacecraft to orbit the moon, provides a backdrop to the display of Galileo’s materials.

“When Galileo looked through his telescope, it gave him a new perspective of the moon,” Clemens said. “I thought it was fitting to include the first Earthrise photo, as it offered all of us a unique perspective of the Earth from the moon.”

…(read more).

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