Tag Archives: exploration

200 years of exploring Antarctica – the world’s coldest, most forbidding and most peaceful continent



Aerial view of a glacier in the Antarctic peninsula region.
Getty Images/Mario Tama

Dan Morgan, Vanderbilt University

Antarctica is the remotest part of the world, but it is a hub of scientific discovery, international diplomacy and environmental change. It was officially discovered 200 years ago, on Jan. 27, 1820, when members of a Russian expedition sighted land in what is now known as the Fimbul Ice Shelf on the continent’s east side.

Early explorers were drawn there by the mythology of Terra Australis, a vast southern continent that scholars imagined for centuries as a counterweight to the Northern Hemisphere. Others sought economic bounty from hunting whales and seals, or the glory of conquering the planet’s last wilderness. Still others wanted to understand Earth’s magnetic fields in order to better navigate the seas.

I am a geologist who specializes in understanding the timing and extent of past ice ages. Much of my work focuses on the glacial history of Antarctica, and I’ve been privileged to conduct five field seasons of research there.

For the next two years I’ll be working with a field team made up entirely of undergraduate students from Vanderbilt University to determine whether the East Antarctic Ice Sheet changes flow patterns as it changes shape. All of the research these budding scientists conduct will be done under the auspices of the Antarctic Treaty, a global agreement that promotes scientific cooperation and environmental protection.

Frozen but abundant

Antarctica separated from South America 35 million years ago, and its climate started to change. It began to grow ice sheets – masses of glacial land ice covering thousands of square miles. As plate tectonics shifted other continents, Antarctica became colder and drier. For the past 14 million years, it has been the frigid continent that persists today.

Antarctica is mostly covered by ice sheets on land and fringed by floating ice shelves.
NOAA

Antarctica is the only continent that was literally discovered, because it has no native human population. British explorer Sir James Cook circumnavigated the continent in 1772-1775, but saw only some outlying islands. Cook concluded that if there were any land, it would be “condemned to everlasting regidity by Nature, never to yield to the warmth of the sun.”

Cook also reported that Antarctic waters were rich with nutrients and wildlife. This drew sealers and whalers, mainly from England and the United States, who hunted the region’s fur seals and elephant seals to near-extinction in the following decades. This hunting spree led to the discovery of the Antarctic mainland and its ice sheets, the largest in the world.

Reading the ice

Today the combined East and West Antarctic ice sheets hold 90% of the world’s ice, enough to raise global sea levels by roughly 200 feet (60 meters) if it all melted. Antarctica is the coldest, highest, driest, windiest, brightest, and yes, iciest continent on Earth. And 200 years of research has shown that it is a key component of Earth’s climate system.

Despite the appearance that it is an unchanging, freeze-dried landscape, my research and work by many others has shown that the East Antarctica Ice Sheet does slowly thin and thicken over millions of years. Interestingly, my data also suggest that as the ice advances and retreats, it moves in the same patterns each time. Put another way, the ice flows over the same land each time it advances.

While East Antarctica adds and loses ice slowly, it is so large that it is a major contributor to sea level rise. Understanding how the ice has changed in the past is key to predicting how much and how fast it will melt in the coming years.

These questions are especially important in West Antarctica, where the bottom of the ice sheet is below sea level, making it very susceptible to changes in sea level and ocean temperature. By itself, the West Antarctic ice sheet has the potential to raise sea level by 16 feet (5 meters) if it collapses.

As climate change raises global sea levels, parts of the West Antarctica Ice Sheet, such as the Thwaites and Pine Island Glaciers, are particularly vulnerable to collapse. At the end of the last ice age, parts of West Antarctica thinned by an average of 1.5 to 3 feet (0.5 – 1 meters) per year. Today with GPS, satellite and airborne measurements, scientists are seeing parts of West Antarctica thin by 3 to 20 feet (1 to 6 meters) per year.

Antarctica is losing ice at an accelerating rate, partly due to climate change.

We also know from the geological record that this ice sheet is capable of rapid collapses, and has sometimes thinned at rates in excess of 30 feet (10 meters) per year. Recent models show sea level could rise by 1 meter by 2100 and 15 meters by 2500 if greenhouse gas emissions continue to rise at current rates and the ice sheet experiences a rapid collapse, as it has in the past.

Finding inspiration in scientific diplomacy

Despite the potential for environmental disaster in Antarctica, the continent also offers evidence that nations can collaborate to find solutions. The Antarctic Treaty System is the world’s premier example of peaceful and scientific international cooperation.

This landmark accord, signed in 1961, sets aside Antarctica for peaceful and scientific purposes and recognizes no land claims on the continent. It also was the first non-nuclear accord ever signed, barring use of Antarctica for nuclear weapons testing or disposal of radioactive waste.

The great Antarctic explorer Sir Ernest Shackleton said that “optimism is true moral courage,” and the authors of the Antarctic Treaty were certainly courageous optimists. They were encouraged by the success of the 1957-1958 International Geophysical Year, a worldwide program of scientific research during which 12 countries built over 50 bases in Antarctica, including McMurdo Station and the Amundsen-Scott South Pole Station.

Flags of the 12 original Antarctic Treaty member countries at McMurdo Station, Antarctica.
U.S. Antarctic Program/Rob Jones

Under the treaty, scientists from North Korea, Russia and China can freely visit U.S. research stations in Antarctica. Researchers from India and Pakistan willingly share their data about Antarctic glaciers.

Thanks to the Antarctic Treaty, 10% of Earth’s land surface is protected as a wildlife and wilderness refuge. I have set foot in places in Antarctica where I know no one has ever been before, and the treaty sets areas aside that no one will ever visit. Antarctica’s landscapes are unlike anywhere else on Earth. The best comparison may be the Moon.

Yet in these stark environments, life finds a way to persist – showing that there are solutions to even the most daunting challenges. If Antarctica has taught us anything in 200 years, it’s that we can cooperate and collaborate to overcome problems. As Ernest Shackleton once said, “Difficulties are just things to overcome, after all.”

[ Thanks for reading! We can send you The Conversation’s stories every day in an informative email. Sign up today. ]The Conversation

Dan Morgan, Associate Dean and Principal Senior Lecturer in Earth and Environmental Sciences, Vanderbilt University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


The Murujuga Mermaid: how rock art in WA sheds light on historic encounters of Australian exploration



The Enderby Island ship image depicting His Majesty’s Cutter Mermaid, which visited the Dampier Archipelago in 1818.
Courtesy: Murujuga Dynamics of the Dreaming ARC Project

Alistair Paterson, University of Western Australia; Jo McDonald, University of Western Australia, and Tiffany Shellam, Deakin University

It is understandable that Captain Cook is a trigger for debates about our national identity and history. However, we often risk being blinded by the legacy of Cook. Around the continent, early encounters with outsiders occurred on other days, and in other years before 1788. Across northern Australia these did not involve Europeans, but rather Southeast Asian trepangers.

The earliest documented European landfall was at Cape Keerweer, Cape York, in 1606 with the landing of the crew of the Dufyken. For coastal Aboriginal communities around Australia each moment of encounter was unique, significant and – in many instances – cataclysmic.

Image of ‘Boon-ga-ree’ by Phillip Parker King.
Phillip Parker King, album of drawings and engravings, 1802–1902, PXC 767, Mitchell Library, State Library of New South Wales.

The history of the exploration of Australia’s coast became a media story with Prime Minister Scott Morrison’s announcement that a A$6.7 million replica of Cook’s Endeavour would be built to circumnavigate Australia. Of course, James Cook never circumnavigated Australia. This was done by Abel Tasman in 1642 (albeit at a great distance) and most effectively accomplished in 1803 by Matthew Flinders.

Flinders was accompanied by Boongaree, an Aboriginal man from Port Jackson, now remembered as an iconic Aboriginal go-between for his ability to move between the Indigenous and settler worlds.

Remarkably, Boongaree would circumnavigate Australia a second time in 1817-18, accompanying Phillip Parker King, a consummate explorer. King would captain four expeditions circumnavigating Australia and filled in many details on the map. He and his crew remain unsung heroes of exploration compared to Cook.

Phillip Parker King c.1817, by unknown artist.
ML 1318, Mitchell Library, State Library of New South Wales.

During archaeological field recording in the Dampier Archipelago (Murujuga), Western Australia, our team working with Murujuga Land and Sea Unit Rangers encountered an engraved depiction of a single-masted sailing ship. This image is on an elevated rock panel in an extensive Aboriginal engraving (petroglyph) site complex near a rocky water hole at the south-western end of Enderby Island.

We argue in a new paper that this image depicts His Majesty’s Cutter (HMC) Mermaid, the main vessel of the historically significant British Admiralty survey captained by King.

‘View of Mermaid Strait from Enderby Island (Rocky Head) Feb 25 [1818]’, in Phillip Parker King – album of drawings and engravings, 1802-1902. Mitchell Library, PXC767.
Mitchell Library, PXC767.

The Mermaid visited the Dampier Archipelago in 1818. It was not the first European vessel to visit – that was William Dampier in the HMS Roebuck in 1699. But King and his crew recorded encounters with Yaburara people. They observed fresh tracks and fires on the outer islands, and described how Yaburara people voyaged between islands on pegged log rafts.

Phillip Parker King, Native of Dampier’s Archipelago, on his floating log not dated, pen, ink and wash and scratching out on card, 7.9 x 11.5 cm (sheet). Transferred from the State Library Board of Western Australia, 2000.
Reproduced with permission of the Art Gallery of Western Australia

Murujuga is globally renowned as one of the world’s largest rock art estates. Our work has documented the tens of thousands of years of human occupation, the extraordinary production of rock art and the historical presence of American whalers.

The depiction of the boat on Enderby Island overlooks the bay where the Mermaid anchored two centuries ago. When they went ashore the crew observed Aboriginal camps, and the formidable rocky landscape. Boongaree went fishing, while the expedition’s botanical collector Allan Cunningham planted a peach pip near a fig tree. While there, it appears someone scratched the image of the Mermaid.

The Enderby Island ship image showing view across Mermaid Strait to the Intercourse Islands.
Courtesy: Murujuga Dynamics of the Dreaming ARC Project.

A scratched technique

There are various surviving documents from the Mermaid expedition, such as log books, day books, journals, watercolours, and coastal views. Interestingly, in their writings, King, midshipman John Septimus Roe and Cunningham all neglect to mention the engravings, and they did not mention making this image of their ship. We are confident the ship was not made by Yaburara people, as the scratched technique used is very different to the surrounding Yaburara engravings.

A) line drawing (by Ken Mulvaney), b) The ship engraving, Enderby Island, c) King’s detailed section of the Mermaid (Phillip Parker King, ‘Album of drawings and engravings’, Mitchell Library, PXC767)
Courtesy: Murujuga Dynamics of the Dreaming ARC Project.

While our investigation suggests that a metal tool was not used to make the image, the imagery – which demonstrates detailed knowledge of the ship’s rigging and proportions, and the inclusions of water in this “sketch” of the craft, leads us to the conclusion that this ship was sketched on the day that the crew of the Mermaid visited this area.

So, who made the image? We really don’t know (but do have some ideas).

The artist clearly knew the ship in great detail. The similarities to the Mermaid are profound, allowing us to rule out other possible vessels to visit the islands in later years such as two-masted whaling barques and pearling ships.

Both King and Roe made many images in their records of the Mermaid – was this one of theirs? Perhaps another unnamed crew member got involved. Perhaps Boongaree was impressed by the extensive rock art legacy that he encountered. Being from Sydney with a similarly rich rock art heritage – which includes the depiction of post-contact sailing ships – perhaps he depicted what was by then utterly familiar to him – a tiny sailing ship on a voyage across the unknown seas.

Whoever’s hand, if this is the Mermaid, as we argue, this new finding is of nautical and historical significance to Australia and Britain as well as being significant to the Aboriginal people of the west Pilbara.

Significant timing

The timing of King’s visit is significant. He was there for eight days in February and March, a time when monsoonal rainfall rejuvenates the rock pools on the outer islands and when turtles were hatching: a seasonal pulse in Yaburara island life.

During that week the crew of the Mermaid described their contact with family groups that were camped on several of the inner islands, as well as the widespread evidence for outer island use. Their encounters with people included the observations of their unique water craft, camps and a range of subsistence activities. One Yaburara man was kidnapped from his mangrove raft, and taken on board the Mermaid where Boongaree tried to reassure him by removing his own shirt to reveal his body marking and black skin. The visitors offered the Yaburara man glass beads, which he rejected.

King’s voyages of discovery left behind other marks along the West Australian coastline. At Careening Bay in the Kimberley in 1820, King had the name of the Mermaid carved into a boab tree, where it can still be found today. At Shark Bay, King had a post erected with “KING” spelt out in iron nails – today this is in the WA Museum.

Mermaid Tree, Careening Bay
Courtesy: Kevin Kenneally

Collections from the Archipelago included plants and stone artefacts still held in the British Natural History Museum. King’s daily journal helped him create his official account, published as two volumes in 1826 titled Narrative of a Survey of the intertropical and western coasts of Australia.

There was no marked national commemoration in 2017 of the 200-year anniversary of the start of King’s voyages. However, as Murujuga’s nomination to the World Heritage Tentative Listing proceeds, this new evidence adds further significance to the Mermaid’s brief encounters with the Yaburara.

It provides new insight to King’s Expedition around this continent’s seascape as well as adding to the deep-time record of Murujuga’s Aboriginal history – and place-making inscribed on this landscape.The Conversation

Alistair Paterson, ARC Future Fellow, University of Western Australia; Jo McDonald, Director, Centre for Rock Art Research + Management, University of Western Australia, and Tiffany Shellam, Senior Lecturer in History, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


A brief history of Martian exploration – as the InSight Lander prepares to launch



File 20180219 75967 1o8sc68.jpg?ixlib=rb 1.1
An artist’s rendition of the InSight lander – which will collect data on what’s inside the planet Mars.
NASA

Helen Maynard-Casely, Australian Nuclear Science and Technology Organisation

Roughly every two years Mars and Earth wander a bit closer to each other, making the leap between these two planets a little easier. In July this year, Mars will only be about 58 million kilometres away – and NASA is set to take advantage by launching their next mission to the red planet in May 2018. The InSight Lander, will be the first Mars mission to investigate the planet’s “inner space”, and will listen for marsquakes to investigate the crust, mantle, and core.

InSight will join two rovers currently exploring the surface of Mars, and 14 spacecraft that are in orbit about it – albeit only six of which are currently sending us data.




Read more:
Ice mined on Mars could provide water for humans exploring space


Why does Mars, the red planet, have such a hold over us?

There are, after all, seven (or eight) other planets to explore – and yet we seem to have such a hang up on this one.

I guess it’s the tantalising nature of Mars. Here is a planet that we could conceivably walk on (unlike the gas giants), without being crushed by atmospheric pressure (like on Venus), having to deal with the radiation of being closer to the sun (Mercury) or just being far too far away (like Pluto). It calls to us through science fiction and fact, a planet that is so like our own Earth, but so unlike it at the same time.

Mars fly-over movie, made by visual artist Seán Doran, via NASA/JPL/University of Arizona.

The six current operational missions show that the fascination with Mars isn’t limited to one country, as European, Russian, American and Indian space agencies all have stakes in these crafts.

For comparison: our other nearest neighbour, Venus, only has one spacecraft currently in orbit about it, Akatsuki the spacecraft that wouldn’t quit. In fact, after the dramatic ending of the Cassini spacecraft, the only other planet currently being orbited by an Earth-built satellite is Jupiter, with the Juno mission.




Read more:
Juno mission unveils Jupiter’s complex interior, weather and magnetism


Water on Mars

But, while our progress to walking on Mars has been very slow, our progress in understanding our neighbour has been really quite impressive. When I started my planetary science degree in 2001, the course did not include sedimentology, the branch of geology that investigates how water has shaped rocks. It was deemed there was no point as no water has been seen on any other planet.

By the time I was in third year, the first years students behind me were getting well versed in how water could push around sand, silt and clay on other planets.

Finding water on Mars had been an obsession to many, and thanks to data from Mars rovers Spirit, Opportunity and latterly Curiosity we know that it’s there – just trapped in the rocks. A couple of years ago it was thought that we had even found water flowing on the surface of Mars, but that evidence is (ahem) drying up now.




Read more:
Dear diary: another day in the life on Mars


However, whether the water flows or is trapped in the rocks, the next question is where is the rest of it? If many of the rocks we see on Mars had been laid down by water – where is that water now?

The answer would be tangled up with the fate of Mars’s atmosphere. Though pitifully thin now, it must have been thick enough in the past to support flowing water on the surface. The mission of the spacecraft Maven (along with others) has been investigating this question – and all evidence is pointing to the Sun as the culprit for Mars’ missing atmosphere, with the solar wind gradually stripping it away.

Mars’ surface

It’s often touted that we know more about the surface of Mars than we do the bottom of our own oceans – and in terms of mapping resolution that’s true. Through the efforts of four orbiting missions we know how old most of the surface is, as well as how active it has been.

You can spend a joyful afternoon of procrastination flitting through HiRISE images that show sweeping dunes and pock-marked plains on Mars. With these images we can really apply our understanding of processes on Earth to what makes up the surface of Mars – from the formations of geological features, the movement of dust and sand and how the ice caps change through the seasons.

What’s inside Mars?

So we know there is water on Mars, we know where its atmosphere went and also the shifts of its sands – but there’s a missing piece of the puzzle. What’s on the inside?

To be fair, in this respect the interior of our own Earth is just as much of a mystery – but we have had centuries of seismic studies. From monitoring the passage of earthquakes through our planet we have built a picture of the layers that make up its interior. From that we’ve been able to undertake experiments that recreate the conditions and add more to that picture. At the moment we can only guess at the conditions within the interior of Mars – something that the InSight mission will answer.




Read more:
Before we colonise Mars, let’s look to our problems on Earth


After this, the next hurdle will be getting something back from Mars. We have a handful of meteorites that we know came from Mars, but having a sample that’s been collected and returned from a known location will priceless. NASA’s next rover, Mars 2020, will plan to do just this – but the return to Earth bit is still to be worked out.

The ConversationFrom sample return to human exploration is still a massive step, and will require a number of innovations to get there. But with the knowledge we’ve built from the missions over the last decade, it’s becoming more of a reality.

Helen Maynard-Casely, Instrument Scientist, Australian Nuclear Science and Technology Organisation

This article was originally published on The Conversation. Read the original article.


Female Exploration



Video: Race for the Poles



Today in History – 30 April 1492


Christopher Columbus: Receives His Commission of Exploration from Castile (Spain)

Christopher Columbus was born between the 22nd August and the 31st October 1451, in Genoa (now in Italy). Contrary to common belief Columbus did not discover America, but he did greatly increase European awareness of the New World.

The maritime career of Christopher Columbus began when he was 10 years old. In the years that followed he undertook a number of journeys on the open sea in various roles on various ships. In 1485 he began looking for an opportunity to explore and discover a western route to Asia. He presented his ideas to the king of Portugal and was ultimately frustrated after several attempts. He also tried England, Genoa, Venice and then Spain (Castile) in 1486. He was frustrated in all these attempts (England eventually agreed, but by that time Columbus was already in league with Castile), but the king and queen of Castile (Ferdinand II and Isabella I) retained his services and after many attempts he finally gained the support of Ferdinand II and Isabella I on this day in 1492.

In all, Columbus would make four voyages between Castile and America. His life would end in great disappointment, having been jailed and having the terms of his contract with Castile overturned due to various claims and convictions of abuse of power and mismanagement of the domains over which he governed in the New World. Columbus died on the 20th May 1506 in Valladolid, Crown of Castile (now in Spain).

 


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