When I described in my last post how rocks can be broken up by volume-increasing reactions happening within them, I left you with several open questions in the end. One of them was whether reaction-driven fracturing can also occur when there is no stress from the outside and no fracture to start with. It is easy enough to imagine that minerals that grow in a crack may push against the walls of the crack, move them apart and cause further fracturing. But for this first crack, with which everything starts, we certainly need some forces from the outside that make the rock break. Or do we really?
In 1972, the scientists onboard the French research vessel Jean Charcot, during the “Midland” cruise made an amazing discovery: Rocks that pop! From the seafloor in the Atlantic Ocean they retrieved some basaltic glassy pebbles that exploded noisily, much like firecrackers and jumped merrily to a height of up to one meter on the ship deck. A decade later, another geologic expedition aboard the RV Akademik Boris Petrov made the same surprising discovery from a complex region of the Mid-Atlantic Ridge that contains vast areas of lava flows (see previous post) as well as heavily faulted terrain with intact blocks of deep crust. These rare forms of lava rock are really interesting because of their spectacular behaviour but mostly because of their richness in gas and information they provide on the deep Earth.
When thinking about your career prospects you may wonder what it would be like to stay at university and go on to complete a PhD with the aim of working in scientific research after that. You may ask yourself what type of struggles you will encounter, or how different it is from working in a company. Or you may just wonder how different it is from undergraduate and master’s level Science studies. Is it for you? Let’s find out.
PhD vs. BSc or MSc
In comparison to studying a degree at bachelor’s level, a PhD will focus on a very specific topic in high detail and at high level, while during your bachelor’s degree you will have covered a very wide range of topics more superficially and written a thesis that is more descriptive or helpful in learning methods and concepts than in advancing science. In comparison to master’s level, it depends. In research-oriented master’s degrees, the master’s thesis or dissertation will be a first taste of what research is actually like, however at a smaller scale. On the other hand, industry-oriented master’s degrees will be more relevant to the interests of a company or industry sector, and may therefore require skills that are more suited to that particular field of industry and applied science.
… and the big black bear
Last summer, I was fighting my way through the boreal forests of Newfoundland in Canada, a place well renowned for its wildlife. Hence I was heavily armoured with big hammers, a huge can of strong pepper spray and some bear banger cartridges in my pocket, always smelling of mosquito repellent and making a lot of noise, in order not to surprise a sleeping black bear in the bushes. In the end, I didn’t need the bear spray or the cartridges, but every now and then signs of bears in our field area reminded us of their presence. And I took these safety measures much more seriously after we encountered a black bear close to a local landfill: you just feel small and vulnerable in front of such a huge, beautiful and elegant animal that is only 20 meters away from you, even if your car is just two meters behind you.
Because some of you asked during ‘La Fête de la Science’ in Paris why minerals have different colors I decided to write this post about it.
First of all, I need to define the electromagnetic spectrum, and the energetic distribution of electromagnetic waves. But what is a wave? Let’s make that clear by looking at waves in the ocean (figure 1).
Abyss Trainess go to Vienna to attend the European Geosciences Union (EGU) 2016 General Assembly
As part of the “Abyss” group, we might wonder what things look like down there, in the deep ocean. As you probably already experienced, diving in water comes with (uncomfortable) changes of temperature and pressure. And that’s only a few meters! The conditions keep changing going deeper in the water column (more than freezing toes!). In oceans, the abyssal waters represent the part lying between 2000 m and 6000 m under sea level. At these depths, the temperature is constant around 0-4°C, the pressure is up to 200-600 atmospheres, and there is no light. And light is not only useful to see around but it is also the energy for photosynthesis and hence life sustenance at the surface of the Earth. Yet, although very poorly known, these depths allow life to exist. And what comes out of discoveries is sometimes very interesting or unexpected!
Life has to adapt to these difficult conditions of low temperature, high pressure, absence of light and scarcity of nutrients. The result is not exactly what we are used to, evolution sometimes leads to cool physical and morphological features! Let’s have a look at some inhabitants of the abysses.
Beyond 100 m in the dark cold water, plants disappear, life in the deep sea is 100% animal, likely because photosynthesis is impossible. With disappearance of light at depth, numerous species evolved to be blind or, conversely, grew big, globular eyes in the attempt to catch any remaining light like our very cute friend in Figure 1.