A big dust storm… in Alaska?

By Phil Plait | November 20, 2010 7:18 am

[Note: At the bottom of this post is a gallery of amazing NASA satellite images of the Earth!]

I need to make a list of the stuff I love about science, because I keep coming up with more. This time, it’s how surprising the Earth can be, even though we live on the dang thing.

For example, when I think of dust storms, I think of China and the Sahara or maybe the Dust Bowl in the U.S. I certainly don’t think of Alaska! But then, NASA’s Terra satellite set me straight:

terra_alaska_duststorm

[Click to 49thstatenate.]

Check that out! An actual series of dust storms blowing off the coats of Alaska! The cause was obvious in retrospect: as billions of tons of glacier flow languidly across the landscape, they crush the rocks underneath into powder called — get this — glacial flour. This gets deposited as mud underneath the glacier. When the glacier recedes a bit, the mud dries, and the wind can blow it away.

Tadaa! Dust storms off the coast of Alaska. Maybe Marian knows all about these, but for me, that’s a first.

The stuff I learn from NASA. Man.



Here are some other amazing images of the Earth from space! Use the thumbnails and arrows to browse, and click on the images to go through to blog posts with more details and descriptions.

terra_10th_first_light
4254627068_8c2dd190e3_o
4943379328_058bf86ee8_o
iss_nile
iss_view_france
midwest_storm2010
nasa_igor
terra_alaska_duststorm
terra_boulderfire
terra_globes
terra_iraq_sand
terra_oil_leak_june202010
terra_seaice

     

Comments (29)

Links to this Post

  1. Una tormenta de polvo ... en Alaska? | November 21, 2010
  1. Gary Ansorge

    So, glacial bump and grind are one source of dust. Guess I should quit blaming meteors for all that crud that accumulates on top of my books,,,

    Cool! I learned something new today and I haven’t even finished my first flagon of coffee.

    Gary 7

  2. Utakata

    …so does that blow all the way over to Russia?

  3. 2utakata
    Most likely. Saharan dust fertilizes the Amazon.

  4. M.K. Oestby

    Fantastic images, thank you very much…

  5. MadScientist

    A common source of dust from Alaska is volcanic ash. Decades after an eruption the wind can still pick up that sand and transport it elsewhere. Unfortunately I don’t have any time to look into what the source may be in this case.

  6. Daniel J. Andrews

    An actual series of dust storms blowing off the coats of Alaska!

    After a hard summer and fall of working in the bush, shooting wildlife from helicopters, coats do get pretty dirty so on a specific day, all Alaskans hang them out on the line and beat them in unison, thereby producing these dust storms. :)

    In the Yukon, we’d get some good small-scale dust storms. E.g. wind blowing across the Slim’s River delta (flowing from the famous Kaskawulsh Glacier, a picture found in many high school geography textbooks) onto Kluane Lake.

    The spruce forest along the shores are very dusty, and I have several pictures taken from the top of Sheep Mountain showing these tall columns of traveling dust blowing across the lake and into the forests (and into the Arctic Research Institute on the shores of Kluane, where you needed to clean your laptop vents at least once per season). These dust storms were mainly in the spring as by the summer the lake levels had risen enough to cover a lot of the dusty deltas. It’s been four years since I moved away, and I can still taste/feel/smell those dusty days when the wind would sweep down off the high elevation ice fields.

  7. MadScientist

    Well whaddayaknow – glacial dust *does* blow out to sea. See this one from 2009 for example (the image coincides with the upper left hand part of the image on the top of the page):

    http://earthobservatory.nasa.gov/IOTD/view.php?id=40973

    I also get a few thousand hits on how ‘glacial dust’ works magic on your gardens. Gee, I try to find out if the dust had been previously imaged and attributed to glaciers and I discover a whole can of woo. If your garden plants show some mineral deficiency, the best (and cheapest) thing to do is to throw in a chemical which has the necessary minerals in a form available to the plants. Using glacial dust as fertilizer is just expensive woo-woo.

  8. The image of the two Atlantic ‘canes kinda reminds me of the spiral galaxies NGC 2207 and IC2163 (turned the other way, of course.)

    As it is down here, so it is out there… :)

  9. Sharon

    When glacial flour gets into rivers and lakes, it gives them that unearthly blue green colour, or sometimes a more milky blue shade. Lovely! I heard all about glacial flour last summer at Jasper and Banff.

  10. More Marian … click my name

    Made the mistake of putting “Vanilla” in the CD player of my car a couple of days later. I haven’t taken a trip long enough to play the whole thing since, so I haven’t been able to eject it. It starts up in the middle when I start my car, and I just think, well I’ll listen to the rest of this song and then switch it for something else, but that just doesn’t work. Help! Something like this hasn’t happened since “American Beauty”.

  11. JimR

    Looks like the Boulder fire smoke olume is blowing to the N. Platte R. Plait2Platte. Any connection

  12. KC

    I went to Alaska recently, and my coat wasn’t blown off even once!!! :)

  13. gypkap

    Maybe they’re just too small, but can big tornadoes be seen from space? When I was a kid in Indianapolis, a small tornado jumped over our house, and destroyed a new garage in a nearby addition. I doubt if that one would be visible from space, but I’ve seen other tornadoes (supercells) in northern New Mexico and the Panhandle of Texas (I think–it’s been awhile) that might have been big enough to be seen from space.

  14. This Nile picture is awesome. I did not know that people are so densely populated alongside the river banks and very sparsely elsewhere. Water is king.

  15. MadScientist

    @gypkap: Features the size of tornadoes are easily seen – after all there are visible imagers in orbit which can record features which are about 2x2feet – they even spot the white line dividing roads since the white paint reflects so much light. However an actual tornado will always be obscured by cloud, so you can bet you won’t see one from satellite even if the bird happened to fly over at just the right time. The geostationary birds can’t see well enough to pick out details on a small scale.

  16. Messier Tidy Upper

    For example, when I think of dust storms, I think of China and the Sahara or maybe the Dust Bowl in the U.S.

    We get plenty of dust storms here in Oz.

    Plus the first place that I think of dust-storms~wise is Mars which has some that cover the whole planet! ;-)

  17. I love the way the streamers of dust are acting as nucleation sites for cloud formation. Giant Alaskan contrails!

  18. Sean McCorkle

    @18 Yeah I was wondering about that too – are the clouds close in elevation to the dust? The striations in both dust & cloud seem to be lined up in the lower right. Fascinating image.

  19. P@J

    Yeah, Geologists know all about this. It is the late-Pleistocene duststorms on the recently-deglaciated upper Mid West that resulted in hundreds of feet of silty “loess” being deposited across the area. This rich silty loam made the grasslands of the Plains one of the greatest argicultural zones in the world, and resulted in the main river draining it all being called the “Muddy Mississippi”. It also explains the sediment-dominated morphology of the Mississippi delta, and… well, Geology explains everything, but I digress.

    Note I said “recently deglaciated”. There is a climate change argument in here somewhere, but let’s not fall down that rabbit hole.

  20. MadScientist

    @sean #19: I doubt the dust (or at least the bulk of it) is at the same altitude as the clouds. The only clue in the image is that you can see the shadow of some clouds cast on the dust plume. Estimating the height of a feature in the visible or infrared remains a challenge. In the infrared the height of the top of an opaque object like a cloud can be estimated from the apparent temperature (however, you can’t tell where the cloud base is), but for a dust plume which is generally not opaque the height is anyone’s guess. The Calipso instrument can provide that information but it isn’t an imaging instrument, so the trick is to get the Calipso range/backscatter data and see where it slices through the cloud and plume. Stereogrammetry from aircraft works, but not from satellites because the birds are too high and don’t have the requisite resolution to give a reasonable estimate of heights.

  21. When we have a big dust storm in Oz like the one in 2007 tonnes of the stuff ends up on the glaciers in New Zealand and apparently some stainage sometimes occurs. Sorry NZ.

  22. Does Sarah Palin know about these?

  23. Sean McCorkle

    @21 I was looking at the shadows too, and agree that the clouds appear to be higher than the dust plumes. There does seem to be a connection between clouds and dust to the right of center of the image, and Bipedal Tetrapods’s idea, nucleation, seems reasonable, if dust can get up to the cloud deck. Maybe the very smallest sizes can be lifted to higher altitudes by convection?

  24. The one to the right of center is most conspicuous, but look at the far left as well – you will notice some waviness to the clouds that also matches the waviness of that dust plume. Though correlation does not necessarily mean causation, in this instance I think it is a safe bet.
    Fine dust could easily rise higher, and also the cloud formation could commence lower, and rise with the heat of condensation.

  25. QuietDesperation

    :shock:

    It’s missile contrails!!!!1!

  26. Jeff

    “I need to make a list of the stuff I love about science, because I keep coming up with more. This time, it’s how surprising the Earth can be, even though we live on the dang thing. ”

    That is correct. I came into this biz 30 years ago from a physics/astronomy background, but now I am teaching and totally focused on earth science. As I’ve become more experienced, I’ve come to the conclusion that the most fascinating planet in the solar system is the earth, and all its beautiful subtleties.

  27. In post 17, Messier Tidy Upper wrote:

    “Plus the first place that I think of dust-storms~wise is Mars which has some that cover the whole planet!”

    Dammit, you beat me to it!

  28. Jason

    Must make it difficult for Sarah Palin to see Russia from her house

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