I actually wanted to start making a post about terror birds last week, but I am glad I didn’t. According to ABC Science, one of the presentations at last week’s Goldschmidt conference (tea time in our department has been somewhat depleted by the amount of people who have gone to it), the mighty terror bird Gastornis was probably a vegetarian. Gastornis lived in the early Paleogene (about 55-40 million years ago), and is thought to have been a plant eater based on its lack of claws, its large size, and calcium isotopes – which matched closer to herbivores than carnivores. Continue reading →
In any case, it’s a cool little display of our active planet. We often forget that it is actively forming and deforming, and these geological phenomena popping up are a great reminder. Even if it does turn out to be from rotting organic matter underneath the ground (which is the other postulated source for it), it’s a good chance to at least reflect on our active planet, anyway :).
My PhD topic involves recreating the Indo-Australian monsoon rainfall over the last 40,000 years using stalagmites from caves. Now, I know that’s a bit of a mouthful and when I tell people that’s what i’m doing I often get met with blank stares and the inevitable question, “what does that mean?”
At the moment I’m putting together a draft paper and yesterday I needed to write my, “conclusions and implications” paragraph. This meant that I actually had to think about what the implications of looking at the past monsoon actually has.
In my musings, I thought that I might try and connect the dots between my paleo-monsoon (i.e. “past” monsoon) record, and the present day monsoon system. In order to do that, I needed to better acquaint myself with the modern monsoon system, and I actually realised that what I’m studying could (if you squint) have real world implications. Continue reading →
Today, I wanted to share a series of snippets of new research that have emerged recently in the field of climate science. These stories have been all neatly compiled by DISCCRS in a weekly mail-out, which I recommend you go and subscribe to!
East Antarctic Ice Sheet Vulnerable to melt
Ancient sediments recovered off the coast of East Antarctica suggest that the ice sheet repeatedly melted back 3 to 5 million years ago, contributing to sea level rise.
A new study published in Nature Geoscience has shown that in the past, the East Antarctic Ice Sheet has melted in response to warmer temperatures.
During the Pliocene, when global temperatures were 2 – 3 ºC warmer than present, the East Antarctic Ice Sheet retreated by as much as several hundred km inland. This new research is important, since it reveals that the East Antarctic Ice Sheet, which has been thought of as largely stable, does respond to changes in global temperature.
The Pliocene, 5.33–2.58 million years ago, represents a warm period in Earth’s climate history, where CO2 concentrations were around 400ppm. This period is often used as an analogue for future climate change, due to the similar CO2 concentrations between then and now. During the Pliocene, global temperatures were 2 – 3 ºC warmer, and sea level was around 25m higher than present.
Scientists drilled a sediment core off the coast of Adélie Land in East Antarctica, and analysed mud found within the core that was sourced from rocks currently found under the ice sheet. They concluded that the only way so much mud could have been carried off to sea is if the ice sheet had retreated inland, eroding those rocks. Continue reading →
Coming from Germany I try to keep myself informed about European news and it’s becoming more and more obvious that there is especially one type of news: the weather.
This year Europe has been experienced a fair bit of freak weather, and it looks likely to be continued.
The year started with one of the longest winters experienced so far. With an average of only 100 sun-hours it was simply dark and miserable. It wasn’t necessarily freezing cold the entire winter (Christmas was unusually warm in some parts) but it wasn’t warm either and by Easter, normally a time with comfortable spring temperatures and sun, Germans had to hide their Easter eggs in the snow (easy to hide, difficult to find). All together it was the darkest winter since records began, with snow until the beginning of April (in the previous years April was the month of record breaking heat waves). Continue reading →
Its been a busy week for Martian discoveries. And all of the stories here are from the Martian geologists that aren’t Curiosity. Remember Opportunity, a rover that landed on the red planet, over nine years ago. Well, despite its initial 90 martian day working lifespan, after 3300 martian days it’s still running, and still producing some great new science.
With all of Curiosity’s success in finding clues as to past water on Mars, Opportunity has discovered this rock, called Esperance. It has lower calcium and iron than any other rock so far analysed by the rover, and far higher quantities of aluminium and silica. Chemically, this means its highly likely to be a clay rich rock. And clay rich rocks can only form where there is high pH (ie. not acid) water.
Opportunity meanwhile, is off on a 2.2km trek for some winter sun, moving 25m on its first day as it trundles off in search of more science!
The pale rock in the middle of the image is believed to contain clays. Image: Nasa/JPL/Caltech/Cornell/ArizonaState
But its not just the old rover’s that continue to function, the satellites are producing some stunning results and images of their own.
A Russian ice station, built on sea ice in the Arctic to monitor environmental conditions in the area has been forced to pack up early due to thinning sea ice. Large cracks have been found in the ice flow on which the station is built, forcing the station to be abandoned months ahead of schedule.
Currently there are 16 scientists working at the Russian station, which “has no chance of surviving through this summer,” according to the head of Russia’s high-latitude Arctic expeditions Vladimir Sokolov.
“The station’s ice floe is cleaved and it was decided to dismantle the station to prevent an emergency situation,” Sokolov told RIA, adding that currently there is no threat to personnel. Continue reading →
Last week there was an amusing situation where some data was suggesting Pavlof’s volcano was about to erupt (seismometers), and then was erupting (thermal imaging), but people on the ground couldn’t confirm it, because, as the volcano is in Alaska and it was a bit cloudy. It cleared up a bit and the eruption was confirmed. Well, the folks on the International Space Station have produced some stunning shots (via Slate.com) of Pavlof’s volcano erupting and the plume spreading for 100s of kms.
Volcano observation from the ISS is actually a very handy tool, as most remote sensing satellites work only in a top down approach. The ability to have a human able to recognise something and look at it from side-on is still quite powerful!
Here’s to that great combination of stunning and deadly.
Note the Slate website have been stealing my obviously original jokes. :p
Some research came out of RSES last week regarding the rotation of the inner core, and how it speeds up and slows down. This research, made by Hrvoje Tkalcic and others, has got a little bit of publicity (http://rses.anu.edu.au/news-events/news/earth039s-centre-out-sync) and also was published in Nature Geoscience last week. In this post, I want to explore a bit of background on how we know what’s happening deep down inside our planet, how this particular research was performed and finally, what sort of significance this sort of work has.
Google (in conjunction with NASA and the USGS) has just released a series of timelapse movies, showing the changes occurring to the surface of our planet since the 1970s.
These videos use images taken by the LandSat satellite over the last 40 years to stitch together the best quality images for key regions around the world, providing a time lapse view of the changes occurring over this time.
Google undertook the mammoth task of sifting through the millions of images taken by Landsat over this time, in order to produce high quality videos, free of clouds and blemishes (wherever possible) allowing a clear view of changes occurring at the surface.
The video below explains the methods used to produce these incredible images, as highlights some of the key regions that have been focussed on.