Total Pageviews

Monday, October 23, 2017

Happy Birthday Earth (at 9 a.m.): Birthday Cake Served Up on a New Plate

     Archbishop Ussher declared today, October 23rd, 4004 B.C. (at 9 a.m.) to be the Earth's birthday. Geologists everywhere will raise a glass this evening to celebrate. . .and serve up a piece of birthday cake on a "brand new" tectonic plate, the Malpelo plate, off the coast of Ecuador. The Malpelo plate is that thumb-like protrusion on the northeast corner of the Nazca Plate (seen below in light blue).





      "Researchers led by Rice University geophysicist Dr. Richard Gordon discovered the microplate while analyzing the junction of three other plates in the eastern Pacific Ocean. Their research is published in Geophysical Research Letters.

     The Malpelo plate, named for an island and an underwater ridge it contains, is the 57th tectonic plate to be discovered and the first in nearly a decade. "Mal pelo" means "bad hair" in Spanish (making the Malpelo plate the patron saint of bad hair days?)





     How do geologists discover a plate? In this case, they carefully studied the movements of other plates and their evolving relationships to one another as the plates move at a rate of millimeters to centimeters per year.


     The Pacific lithospheric plate that roughly defines the volcanic Ring of Fire is one of about 10 major rigid tectonic plates that float and move atop Earth's mantle, which behaves like a fluid over geologic time. Interactions at the edges of the moving plates account for most earthquakes experienced on the planet. There are many small plates that fill the gaps between the big ones, and the Pacific Plate meets two of those smaller plates, the Cocos and Nazca, west of the Galapagos Islands.




     One way to judge how plates move is to study plate-motion circuits, which quantify how the rotation speed of each object in a group (its angular velocity) affects all the others. Rates of seafloor spreading determined from marine magnetic anomalies combined with the angles at which the plates slide by each other over time tells scientists how fast the plates are moving."



      When you add up the angular velocities of these three plates, they ought to sum to zero," Dr. Gordon said. "In this case, the velocity doesn't sum to zero at all. It sums to 15 millimeters a year, which is huge."

       That made the Pacific-Cocos-Nazca circuit a misfit, which meant at least one other plate in the vicinity had to make up the difference. Misfits are a cause for concern -- and a clue.




      Knowing the numbers were amiss, the researchers drew upon a Columbia University database of extensive multibeam sonar soundings west of Ecuador and Colombia to identify a previously unknown plate boundary between the Galapagos Islands and the coast. The Malpelo plate is moving independently of the Nazca plate.





     "Since we're trying to understand global deformation, we need to understand where the rest of that velocity is going," he said. "So we think there's another plate we're missing."

      Let's discover yet another tectonic plate today to serve up that birthday cake! Enjoy, bad or good hair day!
Steph

35 comments:

  1. Thanks for dishing out the goods, mysteries abound below and above us.

    Do we know what time zone the 9 am earth-birth was in? I suppose it doesn't matter to the flat earth society, who wants The Rise in the House of Ussher.

    ReplyDelete
    Replies
    1. Thanks for Usshering in that article, eco.

      I am guessing Greenwich Mean Time since Ussher was Irish.

      Delete
    2. I was hoping for a connection between Greenwich Mean Time and "in the meantime" but, alas, there does not appear to be a connection.

      In the meantime. . .

      Delete
    3. Meaningless and yet meaningful.

      Delete
    4. I can't find the clip or the transcript on this, so you'll have to trust me:
      Frasier Crane: ... "quoth the raven ... nevermore!"
      Coach: Gee, Frasier, you really tell a great story!
      Frasier: Well, thanks Coach, but actually, that was Poe.
      Coach: Naw, Frasier, you're way too modest; it was really good.

      Delete
    5. Great Clip for a bad hair day ;-).

      Delete
  2. According to Ussher's Wikipedia page, 9:00 a.m. on 10/23 is a misquote, and the actual start of the world was 6:00 p.m. the night before. I'd rather leave 10/23 as Mole Day.

    ReplyDelete
    Replies
    1. So should we see a pest removal company, a counter-spy agency, or a dermatologist? Or are we supposed to go to a Mexican restaurant?

      Delete
    2. Yeah, those 15 hours, in the grand scheme of things, makes a huge difference. ;-) I think 9 a.m. makes a better story. 6 p.m. is a tough time to start a new project, anyway.

      I vote for the Mexican restaurant! Viva, chocolate!

      Delete
    3. eco, is that the interior of one of your straw bale houses in your thumbnail?

      Delete
    4. Yes to Mexican restaurants!

      And yes, that is/ was the interior of the house that burned 2 weeks ago. I spoke with the owners last week, they are still a bit shocked but coping well. Hard part is finding a new place to live, they're in a friend's 5th wheel, but that's an imperfect solution.

      Delete
    5. I imagine so. The 5th Wheels look luxurious for on the road trekking, but not for everyday, extended life. Sad for so many.

      Delete
    6. Some other clients have been living in an RV for 3 or 4 years, and they've gotten used to it - they (the RV's) are much more luxurious than the old ones. But my burned out clients also have 3 cats and a dog, and that is pretty close quarters.

      At least they have financial means, really sad for those who were living paycheck to paycheck.

      Delete
    7. Quite an adjustment, I'm sure. I could live in a smaller space as long as Maizie and I had space to roam outside.

      Hoping there's some aid coming to help those who need it most.

      Delete
  3. The Nazca plate was the subject of my senior plate tectonics thesis. How things have changed in PT theory from about a dozen plates to 57 today! (Although, I still like names with a 'Z' in them ;-)).

    ReplyDelete
    Replies
    1. What has caused the evolution in PT theory? Is it better observation techniques from satellites and deep wells? More computer modeling?

      An old college friend researches and teaches this at UC Davis, her Wiki page says

      "Kellogg's main research initiatives focus on understanding the flow in the Earth's mantle that drives plate tectonics, and observing and interpreting deformation in the Earth's crust. At U.C. Davis Kellogg uses numerical methods to model aspects of mantle convection. Kellogg also studies Earthquake Physics and Crustal deformation in order to assess seismic hazard of faults. She also works on the visualization of geosciences data in an immersive environment".

      I read the words and don't understand them.

      Delete
    2. Yes, to all your suggestions, eco.

      Most of the Kellogg paragraph above makes sense to me (especially about mantle convection) but "visualization of geosciences data in an immersive environment" has me scratching my head. . .

      Delete
    3. Now that you mention it, I remember Louise describing her doctoral thesis on the effects of liquid flow in the mantle and plate tectonics. Apparently that was a relatively new theory, not sure if today it is accepted magma dogma (yes, I know magma and lava are different).

      She also works with the wee ones, teaching California kids how earthquakes work, and uses more interactive tools, like boxes filled with very wet sand. I think that's the "immersive environment", too bad Google Translate doesn't have an "Academese" option.

      Delete
  4. Replies
    1. WaPo said so many people were trying to download it the system crashed. Maybe there's hope, though I suspect very few downloaders were from the US, and none from Trumpville.

      Delete
    2. I just read this week's official answers over at Puzzleria!.
      What a coincidence!!

      Delete
    3. Paul, and around 5 years apart in age. . .

      Delete
  5. Replies
    1. Paul, we had so many Painted Lady butterflies here in Sept and Oct they were showing up on radar. Incredible show of the beautiful creatures.

      Delete
    2. eco, interesting about the Wobbles. Apparently there is a band by that name also. Maybe they play only dark songs.

      Delete
  6. Why am I not surprised? If I had any artistic ability, I'd like to do a cartoon of a bunch of adolescent male mammoths gathered near the La Brea tar pits, as one of them gets a running start, bellowing, "Hey! Watch this!"

    ReplyDelete
    Replies
    1. No surprise for me either, jan.

      Tar pits really are the pits.

      Delete
    2. Google, er, Duckduckgo "why women live longer than men" and you'll find all sorts of evidence, this is one of the better ones I've seen.

      Delete
    3. No surprise there. eco, is your new thumbnail of you and other guys doing harrowing stuff? I can't tell.

      Delete
  7. New post on "Even Mammoth Males Took More Risk!" is now up.

    Take a risk and read on!

    ReplyDelete

So glad you visited Partial Ellipsis of the Sun! Please leave a comment and come back soon!