Saturday, 30 November 2013

Lyme Regis

Yesterday I went to Lyme Regis Museum to collect some more samples of the rocks from around the Scelidosaurus dinosaur bones. Here are some of the bones and rocks that I looked at:

Scelidosaurus vertebra

Various Scelidosaurus bones
The museum man knocked off some of the rock from the pieces in the above photo for me to take for analysis, and then he showed me some of his other fossils:

Lots of ammonites!

Ammonite
He then, very kindly, let me chose an Ichthyosaur vertebrae to take home with me! The start of my dinosaur collection!

Vertebrae - with my hand for scale!

Vertebrae

Wednesday, 27 November 2013

Top Trumps!

Today a few of us were helping out at the Plate Tectonics and GeoHazards Conference for A-Level students. First we had to put up some geological posters, and then we were mingling with the students and giving them free-bee bags. We then mingled again at lunch time and again when they were leaving. Didn't really end up doing much geological stuff, but it was good fun anyway! Everybody really seemed to enjoy it, and they got to learn about plate tectonics, earthquakes and volcanoes. The main advantage of the day for us was that we all got a free packet of volcano top trumps, which I plan on playing when my work load dies down! Even better was that Iain Stewart signed them for us, after we managed to tear him away from all of his adoring fans that were getting signatures! Here's what two of us ended up with!

Saturday, 23 November 2013

Land Ahoy!

You may have seen a few months ago that an earthquake created a new island off the coast of Pakistan. This island is around 200m long, 100m wide and 20m high, and formed as two plates pushed together, pushing the seabed up.
A second island, which is also around 200m long, has now been seen off the coast of Japan, a few thousand km's south of Tokyo. It formed after an underwater volcanic eruption occurred, but it currently isn't known if the island will stay, or if it will go.
The National Geographic has gone through other ways in which islands can form. Continental islands were originally connected to a larger landmass, but they broke off as the shifting continents moved apart. They can also form when there is an increase in sea level, covering low lying areas and creating smaller islands.
Tidal islands form when parts of a continent are eroded. The erosion is not complete, but when high tide occurs, it allows an island to form.
Barrier islands lie parallel to coastlines and are made of sediment or coral. Sometimes they form as currents pile up sand on sandbars near coastlines, allowing them to rise above the water. Another way they can form is after a glacier has retreated, leaving behind piles of rock. Floods cause these piles to be separated from the surrounding continent, allowing them to form islands.
Ocean/volcanic islands, such as the one off the coast of Japan, form during eruptions of volcanoes on the sea floor. As the volcanoes erupt, layers of lava are built up, allowing them to eventually reach above the water level.
Coral islands, as the name suggests, are made of colonies of corals that build up to form huge reefs, which can sometimes reach the sea level surface.
Finally, artificial islands are formed by people. They are created from material that is brought in from elsewhere and added to the seafloor, to eventually build up into an island.
I hope you've enjoyed this brief overview of how islands are formed!

Wednesday, 20 November 2013

Out of Earth Experience

Geology isn't just about the rocks, fossils and volcanoes down here on Earth. A lot of interesting and cool stuff happens up in space that can be just as relevant as what we see here. There are two news stories recently that caught my eye relating to this.
The first story is about how the Sun's magnetic field is about to reverse its polarity. This happens around every 11 years on the Sun, and will potentially cause a few satellite problems, but that's about it. Auroras, such as the Northern Lights, are going to be more visible and frequent after the event too. These magnetic reversals aren't limited to the Sun. The Earth itself has also experienced many magnetic reversals in its life. These reversals are very random and do not tend to have a particular cyclicity, as you can see in the picture below.

Magnetic reversals during the last 160 million years (Picture source: JOCMS)
Currently the Earth's magnetic field is 'normal', and the last reversal occurred around 780,000 years ago. A representation of this can be seen in the diagram below.

Normal and reversed magnetic fields (Picture source: Allochthonous)
The Earth is technically overdue a reversal based on the last few events that occurred, and geoscientists believe that that the next one will occur within the next few hundred thousand years. These changes are driven by the changing currents in the Earth's molten core, and the magnetic poles are drifting all the time - currently magnetic north is drifting by around 10 miles per year. When the next reversal occurs, the magnetic field will first begin to fade, leaving us more susceptible to the Sun's rays, and then when it flips, animals who use the magnetic field may become slightly confused, and there may be some impact on our technology, but it won't be the end of the world!
As I mentioned before, the Sun's reversal won't have as much of an impact on us, but it does show that geology doesn't just happen here on Earth.
The second story in the news relates to the research into how Mars lost its carbon dioxide rich atmosphere. Around 4,000 million years ago, Mars saw a decrease in the amount of carbon dioxide in its atmosphere, causing the planet to cool. As I'm sure you are all aware, carbon dioxide is a cause of global warming on Earth, so scientists have been working to see if what happened on Mars would be of any use to here. Rocks from Mars have been found to be siderite rich. Siderite is a mineral that forms during carbonation, where water and carbon dioxide from the atmosphere react with rocks containing the mineral olivine. This obviously takes the carbon dioxide out of the atmosphere, which is why scientists are looking into it further. This process already occurs on Earth, but research is being done to discover if there is any way of using this to lock up carbon dioxide from power stations to hopefully reduce global warming.
Like the previous story, this one also shows how there is a clear link between the geology on Earth to the geology elsewhere, and that understanding the processes that have occurred on other planets may have some advantage to improving our knowledge of the geology here.

Saturday, 16 November 2013

Charmouth

Be prepared for lots of photos! Yesterday I went to Charmouth as part of my MGeol project, which is looking into the theory that terrestrial dinosaurs found in marine rocks were victims of ancient tsunamis. For this project, I am looking into a specific dinosaur called Scelidosaurus, which has been found in Charmouth.

Scelidosaurus bones and reconstruction
I met up with the finder of some of the Scelidosaurus bones, and he showed me some of his samples and took me out to Charmouth so I could collect some of my own. Here are some photos of some of his samples:

An assortment of Scelidosaurus bones

Scelidosaurus leg bone

Crinoids

Large ammonite
Here are some photos of a sample of rock that he let me take from outside the dinosaur bone:

The bone in the rock

A small bit has been chopped off

My sample
Here is a photo from Charmouth:

Some of the areas where we sampled
Here are some of the photos of the samples that I took from Charmouth:

Ammonite

Ammonites

Belemnites

Rocks where Scelidosaurus has been found

Rocks where Scelidosaurus has been found

Wood

Oyster shells and wood

All of my samples!
A side note that some of you may find funny - at one point I got stuck in the mud! It came up to my knees and went in my wellies! I had to be dug out with a spade, and I had wet feet for the rest of the day! Other than that, it was a very fun day, and I got to see some amazing samples. I'm looking forward to working with the ones that I collected, and I shall hopefully keep you updated!

Sunday, 10 November 2013

3D Geology

Obviously all geology is 3D, but some of it isn't visible to us, or is too fragile to be handled for too long, so the development of 3D printing has certainly helped. A 3D printer belonging to Franek Hasiuk, a geologist at Iowa State University, has helped to revolutionise teaching and research. Pore spaces in rocks are tiny voids where oil, gas and fluids hide, and they are very tricky to see. 3D printing has allowed scientists to see these pore spaces, however better quality 3D printers are needed for the smaller pores. Hasiuk's printer has been used to replicate fossils for students to study without the worry of running out of specimens or destroying any of them. All students are now able get a type specimen (the fossil from which the species is described), without fear of damaging the specimens. 3D printing is also useful for students who have vision impairments, as they get to feel things like continents that they wouldn't be usually be able to interact with. For more information, visit livescience.

Saturday, 9 November 2013

Core Samples

On Thursday (sorry for the delay - large amount of coursework recently!) we collected the samples from our cores, after they had been dried.

Dried Samples
We then crushed these samples down and put them through a 63 micrometre sieve so that we could separate out the material. The grains that were under 63 micrometres were put into jars to be looked at later, and the grains that were over 63 micrometres were put into bags so that we can keep all of the material.

Under 63 Micrometre Material

Over 63 Micrometre Material
And that's about it really, sounds simple, but it took us two hours and all that shaking was very tiring!

Monday, 4 November 2013

How to Build a Planet

If you like geology, but you aren't much of an expert, then a lot of things can seem far to complicated and scary. Richard Hammond has a new programme on the BBC discussing how the Earth was formed. I would definitely recommend that you watch it as it's very funny and very interesting, but if you don't have the time, then not to worry, I shall outline the key points below.

The first thing that he looked at was what the Earth is made of. The Earth weighs 6 x 1024kg (that's 6 with 24 0's after it!) and has four basic components: iron (32%), oxygen (30%), silicon (16%) and magnesium (15%). The remaining 7% of the planet is composed of things like hydrogen, aluminium, salt and calcium. These components started off as tiny dust particles as a cloud in space 4.5 billion years ago.
Richard then looked at how all of these components came together to form the Earth. 4.5 billion years ago there was no planet, and hence there was no gravity (if you want to see Hammond floating around in a zero gravity simulator, I suggest you go to around 15 minutes in the video!). This means that something else would have had to have brought the dust particles together, and this something else is an electrostatic force. As the particles were floating around they would have rubbed together, which would have given individual ones positive or negative charges, allowing several of them to stick together. However, this is only affective over a tiny difference, but it does mean that the slightly larger grains would have some gravitational force (which is the attraction of one object to another). This means that a clump of dust would attract another clump, which would in turn attract another clump, and so on and so on, eventually forming rocks, and then larger rocks, and eventually a whole planet. This whole process only takes a few million years.
Gravity is still affecting and shaping the planet today. Meteorites are drawn to the Earth's surface, causing potentially large impact craters. A well known, relatively recent (50,000 years ago) impact caused the Barringer Crater to form in Northern Arizona. The meteor itself was only 30m in size, whilst the crater that it left behind is over 1km in diameter. Scientists have calculated that it would have impacted at 26,000mph, giving it a relative weight of 2 mega tonnes. We still have a lot of meteorite matter reaching the Earth today (around 40,000 tonnes per year), although most of it is dust. When the Earth was forming, around one impact happened every few minutes! This onslaught helped to build the planet.
Hammond then looked at how the surface of the Earth became habitable, as when it formed it would have been molten and magma rich. For magma to cool and become solid, it needs to flow so it can form a crust on top (there's an amazing bit at around 37 minutes where he shows how it cools). This didn't work when the Earth was forming, as it was being constantly bombarded with meteorites, which transferred their kinetic energy into heat energy when they hit, meaning that the Earth's surface couldn't cool down. 4 billion years ago, the meteorites slowed down in intensity, giving the magma time to cool and solidify.
He then went on to explain how water and gas came into existence. The volcanic activity released water into the atmosphere as steam, which consequently formed clouds, which in turn filled the very first oceans. Asteroids and comets also brought some water to the Earth. This volcanic activity also pumped out toxic gases into the atmosphere, making it impossible for life as we know it to develop. Luckily, 3 billion years ago, stromatolites (primitive blobs of bacteria) dominated the Earth, which live off sunlight and carbon dioxide from the water, and they also release oxygen, much like modern plants. This allowed complex life to have a chance.
Richard finally explained about how the moon formed, and it's vital effects on the Earth. As the Earth was forming, a large planet sized rock crashed into the Earth, causing large fragments of rock to be hit off out into space. These fragments clumped together thanks to gravity and eventually formed the moon. The moon helps to give the Earth gravitational stability, as without it there would be a large amount of wobble of the Earth which would cause drastically variable seasons, making it nearly impossible for life to form. The moon also affects the tides, which allowed life to gradually leave the sea, leading to the land animals that we have now. These tides would have been much larger than they are today, but the moon has been gradually moving further away from us (to its current position of 239,000 miles), allowing the tides to decrease and flooding to be reduced.

I found this programme very interesting as it outlined the key bits of information about how the Earth formed, which to someone like me is common knowledge, but to other people without a geological background can be quite complex. A good video to watch regarding this is on YouTube, where you can see how little people really know about the formation of the Earth (although I imagine that anyone who did know something more complex was cut out!). As geologists, we tend to forget that people don't know all of this, as a lot of it is basic to us, but ask us about say basic medical care, or how to programme a computer, or how to write a book and we won't have a clue! I hope you enjoy the programme and/or my overview of the geology!

Saturday, 2 November 2013

Dino News

There's been a lot of news about dinosaurs recently, which is great for me, as I love them. The first news is that the first Tyrannosaurus Rex skeleton to have been discovered is now on display in the Natural History Museum. This dinosaur was found in 1905, and was mistakenly called Dynamosaurus imperious in the same paper that T-rex was first described in. This mistake was soon realised, and can be explained by the fact that the Dynamosaurus skeleton was mixed in with other dinosaur bones. I was intrigued about what bones were mixed in with the skeleton, so I did a quick search and Google Books came up with this, on page 58 - Osborn (1905) named this partial skeleton Dynamosaurus imperious... in particular because of the osteoderms (now known to belong to an ankylosuar...). Osteoderms are bone deposits that form scales or plates on the skins of reptiles and dinosaurs. Ankylosaurs are herbivorous dinosaurs that are known for their plates and spikes on their backs. It is thought that some of these spikes from an ankylosaur were mixed in with the bones leading to the incorrect name of Dynamosaurus to be given.
T-rex's are tiny compared to the dinosaur giants, Sauropods, which are the second dinosaurs to be in the news. The T-rex would have come to knee height on the largest Sauropod, Argentinosaurus huinculensis, which the University of Manchester have been studying to determine how it would have walked. Argentinosaurus weighed in the region of 80 tonnes (that's at least 10 times bigger than the largest recorded elephant), and researchers wanted to find out how their muscles and bones managed to support and move their enormous bodies. There has been some controversy about their findings, as only its legs and part of its spine have been discovered, making it hard to accurately predict how it would have worked. Scientists mapped the muscles and tendons of Argentinosaurus using modern animals as a guide. This information was put into a computer, where a simulated dinosaur robot programmed how to use the muscles to walk (you can see the video on the BBC).

Argentinosaurus simulation
Argentinosaurus isn't the only Sauropod to have been in the news. A rare Diplodocus longus, called Misty, has been put on sale in Europe. It's 17 metres long and lived 150 million years ago, and was found in 2009 by the 11 and 14 year old sons of a palaeontologist. It took a team of palaeontologists nine weeks to dig out the skeleton that looks just like the one in London's Natural History Museum. The bones have been well conserved, allowing Misty to be relatively robust, and it would take two or three people a day to take her down and put her back up again. It's estimated to reach £400,000 to £600,000 when it goes up for auction on November 27th.

Misty the Diplodocus