Science Stuff May 2015

Extreme weather

Sydney storm
Sydney storm

How can we predict extreme weather events like the Sydney storm in Australia last week?

The wild storm that hit Sydney was the result of a weather system called an east coast low.

East coast lows are intense low pressure systems that form off the eastern coast of Australia. They can bring intense winds, flooding events, severe thunderstorms and unusual inland snowfalls. They can cause damage to coastal infrastructure and wreck or beach ships.

The problem is that these systems are hard to predict. They can form very rapidly and they will often form at night.

Lloyds Register Foundation funded research to help predict these extreme events by looking at ocean temperatures.

They supported researchers to study these events, including the east coast low that brought the massive coal ship, the Pasha Bulker, to ground at Newcastle in 2007.

Chris Chambers works on the project, and says ocean eddies are large features in the ocean that contain huge amounts of warm water. “They rotate and move gradually southward down the coast bringing warm water in huge pockets to the regions just offshore. Each of these pockets provides an enormous source of heat and water vapour to the atmosphere.”

“Next to one of these warm eddies there might be a cold eddy. This means that the ocean temperatures might change very quickly over a short distance. This also has an effect on the atmosphere and can strongly affect the rainfall.”

Researchers are now working on improved models of ocean eddies. Simulations of these eddies might tell us when to expect an east coast low.

Name Pluto

Pluto

The New Horizons spacecraft has begun sending back images of the much loved dwarf planet. As it gets closer, we will see features on Pluto’s surface for the first time. Craters, canyons, mountains will appear in New Horizons’ images. But what shall we call them?

A crowd-sourced naming campaign held by NASA and SETI (Search for Extraterrestrial Intelligence) let people vote on a long list of possible names.

Space archaeologist Dr Alice Gorman from Flinders University says, “It’s a wonderful way to get people involved in space exploration.” She believes that “it’s kind of opening it up and making the solar system more democratic.”

As Pluto is the Roman god of the underworld, so the themes for its names are exploration and the underworld.

Alice says there are some good options to choose from including a Yolngu word, Baralku. “It’s the name of the island of the dead in Yolngu culture, which is in northern Australia in Arnhem Land” she says.

“I’m impressed with the more than 40 000 thoughtful submissions,” said Mark Showalter from the SETI Institute, which is hosting the naming website, www.ourpluto.org. “Every day brings new lessons in the world’s history, literature and mythology. Participation has come from nearly every country on Earth, so this really is a worldwide campaign.”

On 14 July, New Horizons will pass Pluto at a speed of around 50 000 kilometres per hour. It will take thousands of images and then beam them back to Earth. At a distance of around 6 billion kilometres from Earth, it will take approximately 4.5 hours for data to get back home.

Scats track quokka cuisine

Quokka

Even though it has the cutest smile in the marsupial world, quokkas still need a good supply of food, water and rest spots to survive.

The biggest population of these adorable marsupials live on Rottnest Island off the coast of Perth in Western Australia.

To help these furry friends, researchers from Western Australian have mapped the plants they like to eat and the places they like to sleep on the island.

“The Rottnest Island population is resource limited,” says researcher Patricia Fleming. “It is likely that loss of a key plant species will alter the carrying capacity of the island.”

Quokkas eat grass, leaves, seeds and roots. To find out the exact plants they eat, researchers collected quokka poo from 210 places on the island and took it back to the lab to dry out and be studied.

After a close look, they found that the quokka diet has changed since it was last studied, 50 years ago. Fire, human influences and the quokkas themselves have all changed the plants that grow on the island.

Patricia also found out where quokkas like to rest – they prefer dense, abundant shrubs for shelter. These comfy spots are especially important at the end of summer when the cold nights arrive – a tough time of the year for a quokka.

This information will help land managers make sure Rottnest Island remains home for quokkas by planting what they like to eat and protecting the places they like to rest.

Scientists revive Brontosaurus

Brontosaurus

The history of the Brontosaurus is long and colourful. Over 100 years ago, there was a race to discover new dinosaurs, known as ‘the bone wars’. Paleontologist O.C. Marsh found many new dinosaurs during this time – in 1877 he described the Apatosaurus and in 1879, the Brontosaurus was greeted as a newly found dinosaur.

Several years later, Marsh’s evidence was revised. Scientists compared both dinosaurs to a new skeleton. They came to the conclusion that all three dinosaurs were the same species. Since Apatosaurus was named first, the name Brontosaurus was relegated to the dustbin.

For 100 years, scientists thought Apatosaurus and Brontosaurus were the same dinosaur. But recently, old information regarding the Brontosaurus has been formally re-assessed.

The researchers studied the evolutionary relationship of different dinosaurs using their remaining fossil bones. They found conclusive evidence that Brontosaurus is distinct from Apatosaurus and can now be reinstated as its own unique genus.

Science is a constantly changing subject, not just a dusty pile of old facts. The Brontosaurus’ resurrection is an example of how new research can change previously accepted science.

Biggest ever asteroid impact found in Australia

asteroid_impact

Deep underground in the centre of Australia is evidence of the biggest asteroid impact in the Earth’s history

It wasn’t just a single impact, but a twin strike from a meteorite that may have split into two as it plummeted towards Earth.

Researchers unexpectedly found signs of the collisions in the middle of Australia, at the tripoint where South Australia, Queensland and the Northern Territory meet. They were drilling almost two kilometres into the Earth’s surface, investigating the geothermal energy in the area.

The drill core they pulled out contained traces of rocks that had turned to glass, a sign of the extreme temperature and pressure caused by a major impact.

The exact date of the event remains unclear. The surrounding rocks are 300 to 600 million years old.

The researcher who found the craters, Andrew Glikson, says it’s all very much a mystery. “We can’t find an extinction event that matches these collisions. I have a suspicion the impacts could be older than 300 million years,” he says.

“There are two huge deep domes in the crust, formed by the Earth’s crust rebounding after the huge impacts, and bringing up rock from the mantle below,” says Andrew.

The two impact zones total more than 400 kilometres across, in the Warburton Basin in Central Australia. “The two asteroids must each have been over 10 kilometres across,” says Andrew.

Robots explore underwater volcano

Pumicerock

When mysterious lumps of pumice stone washed up on beaches in Tasmania, Australia, Rebecca Carey knew that they must be coming from an underwater volcano.

Rebecca is a Tasmanian volcanologist (someone who studies volcanos), and she had been tracking the travelling pumice for more than a year. She knew these large chunks of floating solidified magma were coming from a huge underwater volcanic eruption around 1000 kilometres north of Auckland.

The eruption was first noticed by a plane passenger who saw large rafts of pumice floating on the water.

Rebecca is now travelling to the volcano that produced the pumice, aboard US ship Roger Revelle, to find out more about its eruption. Researchers are keen to take a closer look as we know little about deep underwater volcanic magma eruptions.

“We are interested in how those pumice particles are transported once they leave the vent,” says Rebecca.

Rebecca says the team will use two robots to find out more about the Havre volcanic eruption. One is an autonomous underwater vehicle, called Sentry. The other is a remotely operated vehicle, called Jason.

Sentry is equipped with sonar, cameras, and chemical and magnetic sensors. It will float around, mapping the site and keeping itself out of trouble.

Jason will allow scientists on the ship to access the seafloor remotely. Scientists will pilot Jason down to the ocean bed to collect samples of rock, sediment and marine life.

While the scientists are learning about volcanos, they want you to follow the exploration, and ask questions along the way.

“We have a website which will report our activities and findings in real time, by posting photos of everyday life on the ship and videos of the footage the robots recover.” says Rebecca. “School children are encouraged to follow our voyage online and they will be able to ask the scientists questions.”

Space weather on Friday the 13th

Weeather_space

A minor geomagnetic storm was forecast for around midday (Australia time) Friday the 13 of March. The storm is a result of three solar flares from the Sun that occurred earlier this week.

The coronal mass ejections from these solar flares may strike a glancing blow to the Earth this Friday, according to scientists from the Space Weather Prediction Center at the National Oceanic and Atmospheric Administration in the United States.

Coronal mass ejections are bursts of gas and magnetic fields that are released from the Sun. It takes a coronal mass ejection, on average, 98 hours to reach the Earth.

We don’t feel the effect of a solar flare here on the Earth’s surface because we are protected by the atmosphere and the Earth’s magnetic field. But intense solar flares can disturb high altitude satellites, including geostationary communications satellites and the GPS constellation.

Will these solar flares disrupt our technology and leave us without our Friday night plan? Probably not, as the solar flares observed this week were a tenth of the size of the most intense flares.

They may, however, produce a strong aurora near the North and South Poles. So if you are anywhere near the poles, Friday night could be a good time to turn your head towards the sky.

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