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Intrepid Science
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Welcome to Intrepid Science, the G+ page for Professor Chris Turney and his team.
Welcome to Intrepid Science, the G+ page for Professor Chris Turney and his team.

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Want to learn more about Earth science?

Check out the new infographic from +Intrepid Science

#earthscience #infographic #science #scienceinfographic
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The Tropics and the Furious Fifties
There’s an old sailor’s expression: “Below 40 degrees south there is no law, below 50 degrees south there is no God.” Since the sixteenth century, sailors have spoken in awe of the violent westerly winds and seas they experienced fighting their way across t...

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The Tropics and the Furious Fifties

There’s an old sailor’s expression: “Below 40 degrees south there is no law, below 50 degrees south there is no God.” Since the sixteenth century, sailors have spoken in awe of the violent westerly winds and seas they experienced fighting their way across the Southern Ocean. With few landmasses to slow them down, the winds found across 40 degrees latitude often reach speeds of twenty-five knots—about 40 percent stronger than their northern hemisphere counterparts—earning them the title the “roaring forties.” As shipping pushed farther south, explorers realized that these winds form part of a vast storm belt that includes the “furious fifties” and “screaming sixties,” names more reminiscent of terrible rock bands than a major part of our planet’s circulation system. The early hunters and traders didn’t understand it at the time, but these winds are created by a procession of low-pressure systems carried east by the jet stream, a river of cold air hurtling and twisting round the Antarctic at 10,000 metres. Importantly, something quite profound appears to have been happening in recent decades: The winds seem to be getting even stronger and moving south.

Trying to get a handle on what’s happening in the Southern Ocean, however, is easier said than done. Because the region is notoriously wild, it’s sparse in scientific data. Most of the records we have today come from satellite observations and sporadic records taken by ships as they hastily beat a path to safer latitudes. Fortunately, scattered across the Southern Ocean are a number of tiny pinpricks of land, the so-called subantarctic islands, many of which are home to weather stations that have been taking careful observations since the mid-twentieth century. In the southwest Pacific, the New Zealand subantarctics straddle 48 to 53 degrees south, and lying right under the path of the winds are precious sanctuaries for wildlife, many of whom are suffering a major decline in numbers in recent decades, such as the elephant seals (seen here) and the Rockhopper penguins. Covered in vegetation these islands offer the possibility of finding centuries-old plant and animal remains that preserve a record of the changing impact of the roaring forties and furious fifties.

On the Australasian Antarctic Expedition 2013-2014, we undertook extensive work on the New Zealand subantarctic islands, with a particular focus on the Auckland and Campbell islands. These islands are home to patches of small native trees called Dracophyllum, a shrub that can grow up to 5 metres high. Their importance for understanding the changing weather is thanks to the genius of Leonardo da Vinci. In the fifteenth century, the Italian polymath realized there was a link between the thickness of tree rings and the growing conditions. Thick rings, he reasoned, must have been when it was a good season for tree growth; narrow rings, terrible. Although we have more sophisticated methods than those available to da Vinci, the principle is still the same. By measuring the ring thickness, we can get a handle on changing climate. Dracophyllum is one of nature’s weather stations, putting down a ring of growth each year.

In a paper recently published in the journal Climate of the Past called ‘Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction’, we report the changes recorded by the Dracophyllum trees and compare these to climate models. The trees are truly a remarkable natural weather station, more than doubling the length of the observational record kept carefully by scientists working on the islands. But the big discovery is that since the mid-twentieth century, the trees reveal the climate in the southwest Pacific has become increasingly more extreme, apparently caused by changing winds in the Furious Fifties. Sometimes the wind has weakened, allowing warm airmasses to pass over the islands; at other times, the westerly winds have roared, bringing cold southerly blasts.

When we drilled down further into what was happening, we found the pattern of alternating warm and cold winds matched the climate changes seen in the tropical Pacific, a phenomenon known as the El Niño-Southern Oscillation. ENSO, as its commonly abbreviated, describes changes in tropical ocean temperatures every 2 to 8 years that can have a major effect on the global atmospheric circulation system. The remarkable thing is as tropical Pacific Ocean waters have warmed from the mid-twentieth century, the global climate system seems to be changing too. And nowhere is this more apparent than over the New Zealand subantarctic islands. And as the climate swings from one extreme to another it looks like these changes might be hammering the mammal and sea bird populations that call this part of the world home. Why is the big question? One possibility is the increasingly variable climate is impacting food sources in the region; something we’re hoping to test in future work.

You can download our paper ‘Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction’ from Climate of the Past for free at http://www.clim-past.net/13/231/2017/. Hope you enjoy it.

#AAE #spiritofmawson #CampbellIsland #AucklandIslands #Dracophyllum #DepartmentofConservation #DOC #treerings #SouthernOcean #australasianantarcticexpedition #ENSO #FuriousFifties #ScreamingSixties #RoaringForties #SAM #SouthernAnnularMode #subantarctic #subantarctics #Mawson #DouglasMawson #climatechange #elephantseals #penguins #yelloweyedpenguins #rockhopperpenguins #jetstream #ElNiñoSouthernOscillation #tradewinds #climatechange #globalwarming

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3 steps to thinking like a scientist!

Here at +Intrepid Science we thought we should go back to basics and look at what makes science so brilliant for understanding the world around us. In an age where ‘alternative facts’ are gaining in popularity, this seems particularly timely. To kick things off, we’ve crafted a small infographic on the 3 steps to thinking like a scientist. [Depending on who you talk to or read, the number can vary, with some suggesting as many as 8 steps or more are needed. But the 3 steps won’t see you far wrong]. The important thing is to keep testing your ideas as honestly as you can. The scientific method keeps probing, keeps testing, it never rests. And the great thing is this approach can be used in almost all walks of life: just remember to observe, test and reach the simplest explanation. New data comes along all the time and when something doesn’t fit, it should challenge all of us to reconsider our thinking.

Remember, if it isn’t science, it’s fiction!

#infographic #scientificmethod #criticalthinking #science #alternativefacts #fakenews
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Did life start on Earth 3.5 billion years ago?

Some incredibly exciting results from the Pilbara in northwest Australia! A team of researchers from my very own +UNSW Sydney have found tantalising evidence that the earliest life on our planet started in hot springs on land. The team led by PhD student Tara Djokic at the School of Biological, Earth and Environmental Sciences (BEES) unearthed a host of different features preserved in the ancient rock that include stromatolites – layered rocks built by microbial communities – and gas bubbles trapped by what appears to be an organic substance (basically fossilised goo!) in a part of the Pilbara known as the Dresser Formation which is 3.48 billion years old. Rather wonderfully, the setting is similar to Sir Charles Darwin's early speculations about the importance of "warm little ponds" for creating the right conditions to kick-start life (http://learning.darwinproject.ac.uk/editors-blog/2012/02/15/darwins-warm-little-pond/). The implications of this remarkable discovery are enormous. Not only does this put back the origins of life on Earth by some 3 billion years but it also implies life started on land and then moved into the sea (the opposite to the widely held view that life began around hot vents in the ocean).

Importantly, this new finding might also help guide +NASA's future Mars missions in search of ancient life on the Red Planet (https://mars.nasa.gov/programmissions/science/goal1/). It doesn't get much more exciting than that!

You can read the full research paper 'Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits' in Nature Communications (+Nature Research) for free at https://www.nature.com/articles/ncomms15263.

#Pilbara #Pilbaralife #Pilbarastromatolites #NASA #life #ancientlife #stromatolites #UNSW #BEES #RedPlanet #Mars #MarsMission #stromatolite #geyserite #blacksmokers #hotvents #hotsprings

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It just gets worse! This is the full view of the plaque commemorating Sir Charles Darwin's departure on HMS Beagle in 1831. This special place marks the start of a thirty year journey that would lead to the publication of the revolutionary book The Origin of Species. The world has never been the same since. But you would never know it in Plymouth! Partially hidden by a bin for dog poo, the 'view' is obscured by old fencing being enveloped by weeds. What a mess. Come on Plymouth City Council. This is world history and should be celebrated, not forgotten.
#onlyinplymouth

#sircharlesdarwin #charlesdarwin #darwin #hmsbeagle #beagle #barnpool #originofspecies

@plymouthcitycouncil 
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Amazingly, the plaque commemorating Sir Charles Darwin's departure on HMS Beagle and the voyage that would inspire the groundbreaking book The Origin of Species is hidden away behind a wall, right next to a bin for dog excrement. It seems extraordinary that this quiet part of Plymouth marks the start of a journey that sparked a scientific revolution in our understanding of how our world works. And yet here it is lost off the main path, fighting for recognition amongst the dog poo. #onlyinplymouth

#sircharlesdarwin #darwin #hmsbeagle #beagle #charlesdarwin #originofspecies
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Plymouth: the departure for HMS Beagle and the voyage that inspired Sir Charles Darwin

I'm just back from leave spending a couple of days with friends in southwest Britain. Knowing my love of the science history they took me to a little known spot in Plymouth: Barn Pool, the point of departure for HMS Beagle. Whilst the Beagle's circumnavigation of the planet delivered a rich scientific trove, it's best remembered as the voyage that inspired a young Charles Darwin to realise there was more to the world than the dogma of the time taught. For Darwin it would be a journey that would take nearly 30 years. The sights, scents and sounds of all he experienced laid the foundations for a revolutionary idea: you can explain the wonderfully rich biodiversity of our planet by natural selection alone, without any recourse for a higher being. In 1859, the great man published his scientific arguments in The Origin of Species, and the rest as they say is history.

#onlyinplymouth #charlesdarwin #barnpool #hmsbeagle #beagle
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March for Science - today!

At a time when choosing your own facts is becoming increasingly popular, the world's scientific community is coming together. Without testing your ideas with data, without being honest about uncertainties, without reaching the simplest conclusion, well, it's just fiction.

Show your support. Join a March for Science today (22 April), at a town or city near you.

#marchforscience #withoutscienceitsfiction

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Return to Atlantis

This looks unbelievably brilliant. I haven't heard anything about Damien Hirst for years and he's produced this! A ship wreck rediscovered from an ancient culture and Hirst was asked to help the excavation become a reality. They even found a Mickey Mouse covered in sea shells from 2000 years in the ocean. It's up to you to decide if it's real. What a wonderful concept for an exhibition. I would love to go!

#Unbelievable #MickeyMouse #damienhirst
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