Few people take the time to really understand Earth's plate tectonics. It's one of those subjects in school where everyone's eyes glaze over and they spend their time writing notes to the cute girl next to them, or (nowadays) sexting the girl in the next room.
At any rate, there are fewer subjects that have more immediate impact on our daily lives, and fewer still that anyone pays any attention to.
To visualize this, imagine a cauldron of seething hot molten iron. On the top of the liquid iron are black islands of impurities called slag. That's where we live...on the slag. We are the impurities that float up to the top of the cauldron of molten iron. If you look at a video of this, you'll notice that the little islands of slag move around and bump into each other. That's analogous to the tectonic plates on which the slag floats. Basically, it's a semi-cool skin that forms across the top of the molten material.
Because of the time and size scales involved, it's hard for humans to visualize what the Earth is doing. Earth is a living, breathing organism, and we are parasites on its skin. The Earth expands nad contracts as it respires. It reacts to its environment. It grows and changes on a daily basis, but we are so puny in comparison that we can only notice such things when a large scale change takes place.
Down the center of the Atlantic Ocean is a ridge where the plates are spreading. Simply, liquid rock rises up through a crack and spreads the plates apart. Among the more interesting features of this ridge is that it records the Earth's magnetic polar alignment over billions of years. A fairly simple scanning process results in a series of magnetic stripes that show Earth's magnetic poles flip-flipping quite frequently over geologic time. In other words, pole shift is nothing new, nor does it involve the planet rolling over. Rather the liquid core of the planet is dynamic and as it shifts, the magnetic poles move around. This process is little understood in terms of whether it is caused by inside or outside forces. Nor is it much appreciated that the icing at the spin-axis poles is partially a result of the magnetic poles. Thus, when the magnetic poles shift, ice ages come and go.
Another interesting bit of geologic lore is that at least one plate has completely disappeared. It slid under the west coast of North America and bunched up the overlying land like kicking a rug. The result is the Sierra Madre and Rocly mountains, not to mention a string of volcanoes like Mount St. Helen. Baja and Southern California are also results of this process, and despite appearances, aren't actually part of the North American slag heap.
On a tectonic map, the item to really pay attention to at the moment is the Pacific Plate. You should notice that it's just a big, roughly round disc that covers most of that hemispere of the Earth. The reason this is interesting is that a quick scan of the rim of the bowl will locate places like Japan, the Aleutian Islands, the west coast of North America, Mexico and Chile, the Drake Passage, and the islands of Southeast Asia. A scan of the headlines from the past two weeks should cause a light to go off. This is the legendary 'Ring of Fire'.
This geologic bowl is surrounded with active volcanoes and is currently the site of hundreds of earthquakes ranging from hardly noticable to life-threatening. Just the past few days have seen hundreds of quakes in Sumatera, Japan, Oregon, Mexicali, Mexico, Chile, and the Drake Passage. There's also been a number of quakes down the mid-Atlantic Ridge. Make no mistake, these are all intricately connected events.
Sumatera provides an interesting study, because in the last eight years, we have witnessed several massive quakes with very different outcomes, because they involved two completely different processes.
The 2004 quake, which reached over 9 on the magnitude scale and caused a massive tsunami affecting a significant part of the globe, was a thrust event. Two plates bumping into each other snapped and one side popped up vertically causing a massive displacement of water. Fukushima is another example of a thrust quake.
The quakes last week, in the same region, were strike-slip events, in which the two sides of the fault slide horizontally. This is usually a weaker quake and rarely causes a tsunami, but these quakes are reported to be the strongest strike-slip quakes ever recorded, though only causing a 60cm tsunami (about a 2-foot wave). A strike-slip quake normally doesn't cause a lot of damage, too, much as we saw with these two recent shakers.
So, with some background in place, let's put back for the proverbial Big Picture. I have this little desktop app that gives a read-out of quakes around the world. I have it set to display anything over 5. It was relatively quiet for a long time, but in the last two weeks, it has gone nuts, but in a definite pattern.
Quakes are popping off at very specific and regular points around the Pacific: Honshu, Japan; Drake Passage; Ouxhaca, Mexico; Chile; and Aceh, Sumatera. Almost every quake in the past two weeks has been in a circle surrounding the Pacific Ocean, lterally ON the Ring of Fire. It would take quite a bit of number-crunching and research to determine what exactly is going on, and we can be sure that someone is doing it, but let's speculate on possible causes.
1) Earth is shrinking: since the globe spreads in the Atlantic and converges in the Pacific, the Earth could be contracting and causing the Pacific plate to receive massive amounts of pressure on all sides. As the sides converge, the plate would shift and slide under or over other plates, causing a great number of thrust quakes, as well as large strike-slips, as it tries to relieve the stess. Volcanoes would start popping off all around the region.
This scenario would likely result in a cooling of the Earth's core. Other signs would be a weakening of the magnetic, as well as the mag poles starting to wander around. This event would also likely cause the Pacific Ocean to become shallower, thus causing disasterous sea-level rises worldwide.
2) Earth is expanding: in this scenario, the Earth is expanding and causing a massive release of stress all around the Pacific Plate, as it suddenly has more room to move around and reposition itself. This, too, would likely cause more vulcanism, as pressure was released on magma vents, allowing the swelling core to push more molten rock out the holes to relieve pressure. This scenario would imply a feedback loop of release of pressure, allowing the core to expand more, creating more pressure, causing more release.
This scenario might also imply wandering mag poles, as the core swells and pressure is relieved, it would tend to shift its spin axis, and thus the mag pole axis.
3) Steady-state Earth: this scenario states that the Earth is neither expanding nor contracting, but the continual spread of the Atlantic Ridge causes a continual increase of pressure on the Pacific Plate, which builds to massive release events on an occasional basis.
All three scenarios would explain a great number of observed phenomena right now. Even wild weather events could be traced to large-scale vibrations, the release of tremendous amounts of electro-magnetic energy and a number of other energetic events resulting from mass Earth movements.
A shockwave would stir the atmosphere, causing warmer air to rise and colder air to fall, resulting in huge hail storms, increased tornadic activity, strange seasonal changes, and lower hurricane/typhoon activity.
The massive release of piezoelectric forces would be perceived as anything from strange sounds (horn blasts and random 'crack-booms') to wild electrical storms and plasma events (northern/southern lights). Certainly, there's been plenty of reports of these types of events in recent times. Of special note are active aurora when there's no corresponding solar storm.
Conclusions could run to any of the three scenarios. It would take a lot more time and money than I have to research all the quakes, whether they are thrust or strike-slip, associated land movements, and timings. I'm sure that research is in progress, but whether we little people are privy to it is questionable. It depends on what outcome is expected, I suppose.
In the meantime, we are left to watch and speculate. Since I live in Indonesia, I am paying special attention to these matters. Just this afternoon, there was a 6.5 in the Banda Sea just west of us. We felt it as a minor jiggle for about 30 seconds, with the Chinese lanterns swinging back and forth. If you look at a fault map, Indonesia sits on top of an area that looks like a smashed egg shell, on the southeastern extent of the Pacific Plate. We are in a war zone between the Pacific and Austral-Asian Plates.
The world is basically like one of those number puzzles with 15 tiles and 16 holes, and you have to move them around to get them in the right order. The primary problem in all this is that when the tiles move, people get hurt.
We are at the mercy of forces far greater than we can control. All our wailing and gnashing of teeth about saving the planet just went out the proverbial window. That we assume our activities can have more than a miniscule effect on Earth, or that we can control and master the Earth, are little more than egotistical pipe dreams.
You'd think we had learned this long ago, when King Knutr had his throne placed on the beach and he commanded the tide to stop. He had to swim out of that one. No report as to whether the throne survived. Indeed, folks who think humans have any say whatsoever over natural processes don't get a lot of interaction with Mother Nature.
Come to think of it, Knutr also proved that kings and rulers are pretty much useless, though we haven't learned that lesson, either.
So, as our collective roller coaster clicks and clacks to the top of the first drop, we either choose to ignore the impending plunge, or hold on for dear life. I'm kind of in the middle. One arm is waving furiously in the air, while the other is wrapped firmly around the crash bar.
Here we goooooooo...
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