Greenland’s lost and found forest
Misplaced core sample shows plant bounty, but it’s not good news.
In a bizarre story of lost and found, scientists have learnt Greenland might have been forest green only a million years ago. An international team of scientists, led by Paul Bierman of the University of Vermont, analysed a 1.6km deep, 54-yearold sample of plant-fossilfilled dirt taken from below Greenland’s ice.
They found that the abundance of plant fossils may have meant Greenland was ice free within the last million years – perhaps even only a few hundred thousand years ago. The fivemetre dirt sample was originally taken in 1966 but got lost in a freezer. When it was rediscovered in 2019, Andrew Christ, from the University of Vermont, examined the sample under a microscope and found it was packed full of twigs and leaves instead of just sand and rock.
“Ice sheets typically pulverise and destroy everything in their path,” says Christ, “but what we discovered was delicate plant structures – perfectly preserved.” Their paper, published in PNAS, shows that Greenland was icefree at some time during the Pleistocene – 2.6 million years of repeated glaciation with short peaks of warmth that ended around 120,000 years ago. The Pleistocene was considered a colder time than now, so the ice in Greenland may be very sensitive to a temperature variation, suggesting we could experience another similar melt as our current climate warms, too.
Storm-chasing drones, smart water bombers and a constellation of bushfirespotting satellites could be the key to reducing Australia’s devastating bushfire toll.
Imagine if lightning strikes a tree in a remote valley. A satellite detects it via infrared sensors and notifies a drone. The cameraequipped drone zips to the site, and the blaze is confirmed.
Then a C-130 plane, flying high and safe overhead, drops a watercarrying glider with an automated guidance system over the fire, putting it out before it can become a devastating bushfire.
That’s just part of the ambitious fire-fighting plan being developed by the Australian National University National
Bushfire Initiative. Working with Optus, they plan to launch the satellites in 2022.
Initiative director Marta Yebra says they’re working on a range of technologies that will also monitor fuel loads, moisture levels and weather.
But there’s more. “For example, on-ground sensors for early fire detection – but they have very limited range in terms of the areas…so they can only be mounted in specific places, like places at high risk, or on highways, or places of high ecological value that you want to protect,” she says.
“Then you have another layer that would be cameras mounted in towers that have a bigger range of view, and then we have drones – as we go up we have a larger landscape overview, and then ultimately low Earth orbit and geostationary satellites.”
Drones can be equipped with technology that will identify the driest areas, as well as areas with the biggest fuel loads.
“If you combine that with the prediction of lightning, for example, the drones can chase the lightning storms,” Yebra says. “So you can then deploy them based on fire risk.”
Queensland start-up Fireball International is using similar technology in California, and has started testing in Australia. It recently signed a deal with Space Machines Company to put its satellite into orbit in
2022 using a Gilmour Space Technologies rocket.
Last issue’s object proved tricky to some, but not all. “It looks like a level measuring device, to determine how flat something is (although it doesn’t really look precise enough to be honest),” wrote Evie. Ronakraj Gosalia agreed, “An old-fashioned spirit level… Am I close?” “Like an hourglass, but it uses water, not sand,” wrote previous GTO winner Paul van Leeuwen.
But the winning guess wasn’t even a guess:
“It’s for measuring… the standard electrical volt,” wrote Lana Little, our first correct answer. “My husband Tony took one look…and said, ‘There’s nothing else looks like that – it’s a Standard
Cell, a Weston Cadmium Cell – unmounted’.” Lana added: “Invaluable in the days before we could pop down to the local hardware and snare a pre-calibrated multimeter.” Charles Tivendale also recognised it, but offered this additional delight: “A refill for the old red and black dual typewriter ribbons. The ink is concentrated and stored under oil to reduce evaporation.”