Every two years a group of PhD students disappear into the geological wilderness for the RSES Student Field Trip. In 2014, students spent two weeks camping in the Australian outback investigating the regional geology of Central Australia. After many discussions and presentations about exotic and tropical locations, the student cohort settled on a geological road trip around Tasmania. Here is a quick overview of the geological history of Tasmania and some of the cool sites we managed to visit.
This weeks post is from third year Msci geology exchange student Jesse Zondervan who has been visiting RSES for the last year. This was originally posted on the 10th April on Jesse’s personal blog site.
By Jesse Zondervan
The two week mid-semester break started off with a field trip to Wee Jasper, in the bush of New South Wales. After five days of walking around in a field shirt and hat without phone signal I arrived back in civilization on Wednesday evening. Back in Canberra I spent the rest of my time writing for my assignments and the student newspaper. I also worked on the microscope with Janelle and played some boardgames with the B&G boardgames society.
On the 26th May 2016 I attended the launch of the Geoarchaeology Research Group (GRG) which is headed by Associate Professor Tim Denham (ANU College of Arts and Social Sciences). The launch consisted of a series of short talks presenting the range of topics the group has been working on as well as some input from geoarchaeological researchers from the University of Wollongong. I am definitely not an expert in geoarchaeology and so I encourage anyone who wants to know more about it to check out the GRG website. I just think that the stuff they do is really cool and interesting. It’s also quite important.
Earlier this year I was lucky enough to get to go over to California for a few days all in the name of science. We stayed up in the hills behind Berkeley, a short walk away from the instrument we were using. The view from our hotel room was pretty amazing with views across San Francisco, the Golden Gate Bridge and the Pacific Ocean.
By Tim Jones
The ability to search through colossal amounts of data with a few key strokes is one of the most powerful gifts of the digital age. While vastly improving the standard of common knowledge the world over (with no foreseeable limit to this trend), we have opened up areas of research that would be too arduous for humans, or simply never imagined before the rise of digital data analysis. An awesome example of this is Google’s Ngram Viewer, a corpus of digitised texts containing around 6% of all books ever printed. Linguists use it to track changes in language through time, e.g. the usage of “burnt” vs “burned” or the emergence of phrases such as “it takes two to tango”. I’ve used it to track the occurrence of four words between 1800 and 2000; physics, chemistry, biology, and geology. There are some interesting correlations that can been drawn between trends in word usage and the timing of developments and discoveries in these fields of science. For example, geology begins its greatest period of growth from the year 1829, one year before Charles Lyell began publishing his seminal work, Principles of Geology.
Last year myself and fellow PhD Jessica Lowczak organized a geological field trip for 19 students through Central Australia. This was one of the most rewarding things I’ve done, and despite there being many a stuff-up along the way, I am quite proud of the experience as a whole. It is nearly 2016, and therefore time for the new cohort of students to start thinking about where they want to go on the next trip, and how they are going to organize it.
When I began studying geology, I remember my first-year lecturer telling us that we would “never look at a rock in the same way again.”
Before I started uni, I didn’t think much about rocks. They were just there, kind of boring grey or brown, sitting on the ground. But now I know that every rock has a story.
A new report in Science  is dealing with a striking and so far mysterious feature of the lunar surface:
An asymmetric distribution of large lunar basins.
Large in this case means, that the basins diameter exceeds 200 km and that the formation of the basin thinned the crust to an extend that could be picked up by NASA`s GRAIL mission which measured the thickness of the lunar crust.
If you count these large basins on the nearside and the farside of the Moon you`ll find 12 of them on each side (excluding the very old and very big South Pole-Aitkin basin). And that is what you expect for a Moon that is getting hit randomly by impactors like asteroids and comets.
So where is the asymmetry? It shows up when you look at the size of these basins:
The basins on the nearside are (in average) bigger than those on the farside (Fig. 1). Eight basins on the nearside are bigger than 320 km in diameter whereas there is only one of this kind on the farside.
A possible explanation is that bigger (or faster) impactors favourably hit the nearside. But there is no reasonable mechanism which could explain this behaviour of the impactors. So it could only happen by chance. A chance that is lower than 2%. And that is not a very satisfactory scientific explanation.
As the impactor properties couldn`t provide an answer the team that published the paper had a look on the target properties, meaning the surface of the Moon. And once again, another striking feature of the Moon’s surface, the Procellarum KREEP Terrain (PKT) on the nearside, plays a major role. The origin of the PKT itself is still not a closed issue (I wrote about that here). However it already existed at the time when most of the big basins were formed. And one of the PKT`s main properties is that it is enriched in heat-producing elements (due to their radioactivity). The presence of these elements might have warmed the nearside crustal and upper-mantle rocks (or at least big parts of it) considerably compared to their farside counterparts.
What effect would that have on basin forming impact events?
In the modelling on which the report is based, the team found that in the initial stage of the basin forming impact there is little effect caused by the target temperature. This stage, which is mainly characterized by growing of the crater and ejection of material from within the growing crater, is mainly affected by the impactor properties (speed and mass).
However the target rock properties come into play in the next stage, when the formed crater is modified by subsequent processes. In this stage the mantle below the crater is uplifted (as there is no or much less crust above it, holding it down). On the warm nearside this uplift is much stronger and occurs over a wider area. The basic principle behind this is that warmer rocks can be more
easily elastically deformed than colder rocks. The uplifting mantle prevents the crater rim and surrounding crustal material from collapsing into the crater (“This is my spot!”). On the farside, where this isn`t the case, a lot of crustal material
collapses into the crater. Therefor those basins look much smaller for the GRAIL mission as it detects the thickness of the crust and it cannot distinguish between normal crustal material and crustal material that fell back into the basin. If one accounts for this target related effects on the crater formation the size distributions of the lunar basins look pretty similar on the near- and farside (Fig. 2).
This gives a neat explanation of the observed asymmetry of the large lunar impact basins and similar process might account for weird basin size variations on other planets, especially Mars. It also might mean that we have overestimated the impact flux recorded in the lunar surface as the production of the big nearside basins can be explained with smaller impactors than previously thought.
“P.S.: I came across the paper through a fairly new blog. The site adds (on a daily basis) links to recently published papers that are related to cosmochemistry. So if you are interested in that field it might be worthwile checking it out: http://cosmochemistry-papers.com/ ”
 Miljkovic et al., 2013. Asymmetric Distribution of Lunar Impact Basins Caused by Variations in Target Properties. Science 342, 724-726.
Earth Science Week is an annual event, aiming to help the public gain a better understanding and appreciation for the Earth Sciences and to encourage stewardship of the Earth. This year’s Earth Science Week will be held from October 13-19 and will celebrate the theme “Mapping Our World.”
Earth Science Week 2013 aims to engage young people and others in learning how geoscientists, geographers, and other mapping professionals use maps to represent land formations, natural resource deposits, fault lines, geologic heritage, and more.
As part of Earth Science Week, Geoscience Australia will be running a series free public events around Canberra, including a photographic competition and a geocaching activity. Continue reading “Earth Science Week 2013 in Canberra”
Thanks to the wonders of social media, I just noticed a small volcanic vent (a fumarole) has popped up right near Rome’s airport. Footage of the little vent in action is shown here: http://www.liveleak.com/view?i=94f_1377581556
In terms of discussion about this, there hasn’t been a heap getting out there since the fumarole was noticed on Saturday. The most detailed news report so far is by the Telegraph in the UK (http://www.telegraph.co.uk/news/worldnews/europe/italy/10265372/Volcanic-geyser-erupts-close-to-Rome-airport.html) and a tiny bit more technical info is given by http://www.volcanodiscovery.com/view_news/36609/Rome-Italy-new-fumarole-near-Fiumicino-airport.html but there’s not too much more information out there (and I’m also far from a vulcanologist, so I won’t add any more of my own commentary).
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 :).
To get one thing straight from the beginning: What I don`t want to do in this post is to discuss different Moon hoax theories, and the “evidence” for them (e.g. Fig. 1), as well as the arguments that were laid out to counter these Moon hoax claims. There are enough websites and videos out there already dealing with that matter. For those who are interested in that, this video might be a good one to start with.
What I want to do is the following gedankenexperiment: If the Moon landings were faked, were do the samples come from?
What do I mean by samples?
According to the Lunar Sourcebook (HEIKEN et al., 1991) the six Apollo missions that landed successful on the Moon brought back 2196 samples, which by 1989 were split up into 78,000 subsamples. This splitting allows NASA, apart from doing there one research on the samples, to send subsamples to researchers all over the world and let them study the samples. That means the rocks were and are intensely studied. How intense? Well if you want to get an idea about that you can browse a bit through the Lunar Sample Compendium. There you find summed up the relevant information gathered over the years on each sample. Of course not all samples are studied to the same extent. You`ll find samples like the impact melt 14310, which has a two and a half site reference list alone, or samples like 14425, which has “only” nine references. As it is a glass sphere – 0.8 cm in diameter – that is still quite impressive. All in all, there is a lot of information available about the samples.
I guess, on this basis I can assume everyone agrees that these samples exist?
“No, because the bastards at NASA faked all the research on the samples and all the people who supposedly worked on the samples all over the world are part of the cover-up of the Moon hoax!”
Please. Do yourself a favour. Take a long walk in the park to get some air.
Okay, back to the topic. If we accept the existence of the Apollo samples the interesting question arising is:
Where are they from?
Well there are two answers to that question:
1.) They are from the Moon.
2.) They are not.
On the first option: Under the assumption for our gedankenexperiment that the Moon landings were a hoax, how do we get the samples to Earth?
The LHB, or the ‘Late Heavy Bombardment’ may be the earliest ‘late’ event you have ever heard of. It happened around 4 billion years before you were late for school, and made our planet a particularly unpleasant place to be.
Geologists have a nice name for the period between the formation of the planet and ~4Ga (geology shorthand for 4 billion years ago); we call it the Hadean. Those of you familiar with Greek mythology, or Disney’s Hercules, will know Hades was the god of the Underworld, the guardian of Hell. It is after hell that this time was named, and rightly so. For the first hundred million years or so the earth is not yet solid, it’s a big ball of mixed up melted rock and metal. Later the planet cools down a bit and things are looking up, until along comes the LHB; three hundred million years of continuous bombardment by meteorites.
This post isn’t about how to talk at conferences (even though they contain strangers), nor is it about the ‘elevator pitch’ sort of thing. What I’m on about today is something a bit less defined: how do you talk to random strangers who are interested in your science? Below, I’ll provide some examples and some strategies for people to help, and I’m also looking for people to share their own stories of when they’ve done this or their own strategies they have found successful.
Continue reading “Explaining your science to strangers”
Again for our Canberra based audience here is a public lecture to mark on the calendar. Don’t say I didn’t give you enough warning:
Dr Richard Blewett from Geoscience Australia will present a public lecture titled Shaping a Nation: A Geology of Australia at CSIRO Discovery on Wednesday 10 April at 6pm. The lecture will take the audience on a journey through Australia’s long and complex geological evolution and explore how this geological legacy has shaped the Australian nation.
Refreshments will be served following the talk and one lucky person will win a copy of the recently published book Shaping a Nation: A Geology of Australia. Bookings required via theInspiring Australia ACT website.
For more booking information contact firstname.lastname@example.org or call 02 6246 4646 and donload the flyer here:
Chris Hadfield, commander on the International Space Station, has been capturing the attention of the followers of social media recently. Besides interactions with former Star Trek cast members, he has been posting some amazing pictures. Here are some of my favourites (mostly earth science related).
Continue reading “Chris Hadfield on the International Space Station”
By Nick (originally posted 16th May 2012)
Want to know the secret of happiness? Whisper it quietly, but the answer might be to study geology.
A national student survey in the UK showed that Geology students are the happiest with their degree. An overwhelming 95% of geology studying respondents were happy with their degree.
by Brendan (originally posted 17th May 2012)
Earlier this week, Mike and myself wrote about a period of dramatic growth of the Molowai submarine volcano, part of the Kermadec arc to the north of New Zealand. This morning I came across a good video from 3NewsNZ that describes the Kermadec arc/trench environment and includes many of the features that make science videos cool, including black smokers, false colour bathymetry, strange marine life forms and even sharks.
You can find the video here – http://www.youtube.com/watch?v=IzvhPtxP37w