Friday Headlines, October 18, 2013
THE LATEST IN THE GEOSCIENCES
Earthquake in the Philippines
Life in outer space?
Finding dinosaurs along the pipeline
They found the Chelyabinsk meteorite, and then it broke
At about 8:00 am local time Tuesday the 15th (this would be about 8:00 pm Eastern Time on Monday the 14th), a magnitude 7.1 earthquake struck the Philippines. At this point, at least 144 people are reported dead and many important and historic buildings have collapsed.
Earthquakes and volcanoes are common in the Philippine Islands due to their tectonic setting. These islands lie within what is called the “Ring of Fire” along the margin of the Pacific Ocean. The Ring of Fire gets its name from all the volcanoes that dot the edge of the ocean. These volcanoes (and earthquakes too) are due to the subduction of the Pacific ocean floor under the continents. Another way to think of it is that the continents are over-riding the Pacific Ocean.
You can learn more about the process of subduction here.
The Philippines are bounded on both the east and west sides by subduction zones, shown by dark lines with teeth on them (the little triangles) on the map below. The teeth are always on the over-riding plate. You can see that the Philippines are over-riding oceanic crust from both sides, which makes for a very complex tectonic situation.
The map above shows historical earthquake activity within and around the Philippines. The different colored circles show earthquakes that have happened since 1900. The different colors represent the depth in the Earth the earthquake took place, and the size of the circle indicates how strong the earthquake was.
This most recent earthquake did not occur along any of the larger subduction zones, but along a smaller fault not visible in this map, near the most northerly blue dot.
I admit, this story was a little disappointing. I was expecting to hear about spectral surveys that included evidence for ample carbon, and maybe even amino acids. I think the headline is a little misleading.
Yet, once I’m over my disappointment, it is a rather interesting discovery.
What’s been found is a dying star called a white dwarf. When stars (like our own Sun) burn out of atomic energy, they basically implode upon themselves, resulting in the formation of a white dwarf star. The white dwarf will continue to twinkle for a few billion years before it finally goes out. But in the process of imploding, the star will destroy most of the planets that might have been orbiting it. Some of the remnants of these planets then continue to orbit the dwarf star. And thus begins the story.
Astronomers found a white dwarf with planetary debris orbiting it, mostly dust. They were surprized to see that there was a lot of the element oxygen in the dust. Oxygen isn’t all that common in such dust clouds. This was unexpected.
Their hypothesis is that this oxygen was once bound to hydrogen to make water. The hydrogen, being a very light element, is gone from the dust cloud, but the oxygen remains.
Because water is essential for life (on Earth), the presence of abundant water in a system light years from Earth suggests that life may have been possible – at least before the planet was annihilated by the star’s implosion.
My gripe with this is this constant notion that the presence of water equals the presence of life. Sure, life as we know it on this planet is dependent upon water. That does not mean that life anywhere else in the universe is equally dependent upon water, nor does it mean that the presence of water is a clear indication that life was there too.
Nevertheless, the discovery of water in a distant system is significant. That by itself is a worthy story.
This has happened before, and it will happen again. Whenever construction crews start digging holes with backhoes, there’s always the chance that they’ll turn up something really exciting. (Remember Snowmastodon?) Last week, while operators were digging a trench for a new oil pipeline in Canada inadvertantly uncovered a nearly complete section of the tail of a large dinosaur.
— Terry Reith (@TerryReithCBC) October 3, 2013
Paleontologists from the Philip J. Currie Dinosaur Museum and the Royal Tyrell Museum were called in immediately to assess the fossil and to attempt to collect it and any other parts of the skeleton yet undiscovered.
On February 15th of this year, a meteorite streaked across Russian skies, causing a massive explosion that hurt more than 1000 people.
The meteorite has been called the Chelyabinsk meteorite, because it most affected the Russian town of Chelyabinsk. Parts of the meteorite are known to have fallen into Russia’s Lake Chebarkul.
On Wednesday, a 1250 pound chunk of the meteorite was pulled from the bottom of the lake. Once it was on the surface, the rock broke into three smaller pieces, and then broke the scale upon which scientists were trying to weigh it.
I guess it’s not done with destruction or mayhem just yet!