Friday Headlines, October 25, 2013
THE LATEST IN THE GEOSCIENCES
Blood found in 46 million year old mosquito
Japan has another earthquake and tsunami advisory
…but that doesn’t mean Jurassic Park is a possibility.
A fossilized mosquito was found in a shale layer in Montana dating back to around 46 million years ago. This is different from the Jurassic Park scenario in that the rocks are still about 20 million years too young to have dinosaur DNA and that the fossil came from shale not from amber.
Another important difference is that there is no DNA preserved at all. The proof that there is blood in this mosquito is the presence of iron (which causes the red color of blood) and the molecule porphyrin (which is a component of hemoglobin, the molecule that carries oxygen through the blood). The presence of both of these means that the mosquito had a blood-filled belly when it died.
Sadly (or happily, depending on your perspective), the fossil is much too old for any DNA to have been preserved.
Nearly two years ago, Japan was struck by a catastrophic earthquake that resulted in a massive tsunami. Today, they had another earthquake.
On the Richter Scale, a change from one unit to the next (like magnitude 1 to magnitude 2 or from magnitude 8 to magnitude 9) doesn’t mean that the earthquake was twice as powerful. A change from one magnitude unit to the next means an earthquake was 10 times more powerful. Thus A magnitude 9 earthquake is 100 times as powerful as a magnitude 7 earthquake.
So, while this new earthquake was similar in position and in motion to the 2011 earthquake, it was not nearly so powerful. There was a tsunami advisory, but it was only for a smaller, 3-foot, wave, and unlike the 2011 quake, there was no warning for the rest of the Pacific Ocean.
The map of Japan shows where the epicenter of the earthquake was located.
Notice how the earthquake lies near a deep trench along the eastern margin of Japan. This trench is part of a subduction zone, where the Pacific Plate (basically the ocean floor below the Pacific Ocean) is passing below the islands that make up Japan. Volcanoes and massive earthquakes are associated with subduction zones. Both of these phenomena are common in Japan.
The good news for this earthquake is that no consequential damage has been reported. We don’t want a repeat of the 2011 quake.