Scientists from Penn State claim to have found a new living bacterial species a couple of miles into the Greenland ice sheet. They estimate that the bacteria have been trapped there for about 120,000 years, and have apparently survived in the extreme conditions so far under ice. This is a pretty cool discovery in several aspects, and the news piece on Penn State Live explains it very well:

The microorganism’s ability to persist in this low-temperature, high-pressure, reduced-oxygen and nutrient-poor habitat makes it particularly useful for studying how life, in general, can survive in a variety of extreme environments on Earth and possibly elsewhere in the solar system.

In my recent article on the dinosaur asteroid impact, I mention that scientists believe that could have spread micro-organisms from Earth into space, and with the newfound persistent form of bacteria life, they might be able to survive this kind of event and settle on another celestial body, even if it’s colder and icier than Earth.

Another thing worth mentioning about this discovery is the method they used to dig up the bacteria from these seemingly unreachable depths. Ice core drilling is used in a lot of scientific areas, like research in prehistoric biology like this, but even more in climate research, where ice cores act like a recorder of a lot of useful climatic states and events. From the Wikipedia article on ice cores:

The variety of climatic proxies is greater than in any other natural recorder of climate, such as tree rings or sediment layers. These include (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires.

A lot of research is being done on ice cores right now, and it is of particular interest in our times of climate changes and debates on the issue. With the added probability of finding exotic life forms in these extreme conditions, we should encourage the research even more. There is really a lot of things to learn down there.

Researchers at the University of Utah have compiled the data and come to the conclusion that an earthquake can trigger other earthquakes thousands of miles away (even at opposite ends of the world (almost)).

When an earthquake happens, there are several different types of shockwaves released. The first waves sent out are called P-Waves (for pressure), which behaves much like a sound wave, only traveling through the earth insted of air. Alongside these, there are so called shear-waves, which are waves moving from side to side. Next are two types of surface waves, Love waves and Rayleigh waves (i recommend checking out the links for all these different waves, wikipedia has nice pictures explaining what types of waves these are).

Now enough with the boring definitions, the nitty gritty of it is, that they looked at the data for over 500 earthquakes, and found big increases whenever the surface waves (Love and Rayleigh) came over a certain area. To me this is pretty remarkable, as I’d imagine that these surface waves would be HEAVILY dampened by the time they reach those far-away places, and yet they are enough to trigger seismic activity. As an example, they noticed that the 2004 earthquake in Sumatra (that caused the Tsunami) managed to trigger earthquakes all the way over in Europe!

Now this is obviously all very cool, but they really do not know WHY this is happening yet. All they have done is look at the data and they can clearly see that the seismic activity is way up whenever those surface waves come knocking, but the actual physics behind it have not yet been determined. If you are interested in reading more about this (including a postulation on what might be the cause) you should check out their press-release.

Alright, right out of weekend mode (not a lot of press-releases there) and into week-day mode. A new website, called the Virtual Seismic Atlas, has been opened as a collaboration between University of Leeds and University of Aberdeen (and funded by various energy giants), that gives free a bunch of geological interpretations of seismological data that gives insight into the composition of the earths crust (and what’s to be found under seabeds). This is the kind of data used by oil companies to find oil wells and such, i’ll admit that i had a quick look and realized i had no idea what i was looking at, so it’s probably not something that the general public is going to wet their pants about, but i’m sure that for scientists not given access to this rather exclusive data before, and of course students of geology/geophysics etc, this is great news.

The data is processed from making controlled earthquakes, which is a fancy way of saying “Blowing shit up” (although there are other ways to shake the earth, but you get the idea), in scientific terms it’s called reflection seismology. The earthquake/explosion sends shockwaves through the earths crust, that are then reflected off of various compositions in it. By measuring the time it takes for it to come back, they can tell how far down it is (i’d also imagine that the strength of the reflected wave will tell them something about what it is that reflected it, but i could be way off on that). It’s more or less the same principal you’ll see in radars, where they send out electromagnetic waves and see how/if they are reflected back.

As you may remember from a post on advancements in lightning modelling, i’m a bit of a lightning fanboy, and i’m even more of a laser fanboy, so this news makes me cream my pants. The basic idea behind lightning is that electric charge forms in a cloud and results such a strong electric field that it ionizes a channel of air between the cloud and ground, forming an excellent conductor (ionized air is a great conductor). This results in the lightning strikes you see, a massive amount of current flowing from the cloud down to earth through this ionized channel of air.

What the European researchers have done is use a pulsed laser to artificially ionize air to trigger lightning (see official report here). Now they have NOT been able to create a full cloud to ground lightning, what they have been able to achieve is to see that the in-cloud lightning activity was increased in places where they aimed the laser. They are however working on getting a full cloud-to-ground lightning going, by increasing the power and efficiency of their pulsed laser in hopes of being able to maintain the ionized channel well enough to obtain full lightning.

Now this would not be a completely groundbreaking thing to do. Scientists have been inducing lightning for years now using a more crude method that has about 50% success rate. They “simply” shoot up a rocket into the cloud that has a conducting wire connected to it (so now the lightning travels through the wire insted of an ionized channel of air). In fact the accompanying picture with this article is of just that (you can look here to read more about it). But if they succeed at doing this it would cut costs, time and effort required to obtain this and could potentially have some new applications as well. Any way you cut it, laser induced lightning is just cool as hell.

Not even sure if that qualifies as a pun, but stay with me here! In a press-release from Penn State, we hear that researchers there have now created a model that sheds light on in what conditions different kinds of lightning form. While the model does not really offer any predictive powers, I still find it quite cool, and I’ll grab the chance to write about something as awe-inspiring as lightning.

Lightning happens when electric charge escapes from the clouds and down to Earth. But there have to be rather specific conditions for this to happen, because air can not normally conduct electric charge. So what happens is that a cloud starts forming an electric charge somehow (and just how it does this is still up for debate), reaching very high voltage differences between the clouds and the ground. Once this difference is large enough, a process called dielectric breakdown happens, which basically means that the air becomes partially ionized, which in turn means that it can now conduct electricity, and transfer large amounts of electric-current down to the ground, striking golfers at will. The resulting sound you hear is because the extreme energy from the lightning heats up the air around it, which causes it to expand quickly, causing the boom. The video below shows a typical cloud-to-ground lightning as you’ve probably seen before.

This is at least the “normal” lightning as most of us think about it. There are however many different kinds of lightning, and in fact, most lightning never hits the ground, but travels within the clouds themselves. There is also another kind of lightning that goes from the cloud and to the ground, but is very different from a normal lightning. It is what is known as “Bolt from the blue” lightning, because it can indeed strike in what may seem like a clear, blue sky! This kind of lightning can travel 10’s of kilometers away from the actual storm cloud before making touchdown, and to top it all off, it is a lot more powerful than your run-of-the-mill lightning. The video here shows the lightning travelling inside a cloud (sorry, couldn’t find any video of a “Bolt from the blue”, but the picture on top shows one).

The research done by the Penn State team explains how and when these “Bolts from the blue” are created (using a mixture of observation and computer modeling) , as well as the other types of lightning. To quote the press release:

Our explanation provides a unifying view of how lightning escapes from a thundercloud
…
For intracloud lightning, the most common form of lightning, the transfer of charge occurs between the most negatively and most positively charged areas, the middle and upper parts of the cloud, respectively. Lightning that strikes the ground does so because precipitation or the storm’s progression creates an excess of net negative charge in the mid-levels of the cloud. This results in either a direct ground strike or a bolt from the blue.

I’m always in awe of lightning when I see it, it is truly amazing watching them and thinking of the power that nature possesses to light the entire sky up like that. For some perspective on their power, a normal cloud-to-ground lightning strike has 500Mega-Joules of energy and carries an electric current of around 1000 kilo-Amps. And now to put THAT into perspective, 0.01Amps is the lowest current a human can feel, 0.1-0.3 is enough to kill, and 6Amps is what you use in a defibrilator, compare that to the 1.000.000 Amps in lightning (figures taken from wikipedia article on electric shock).