illconsidered

Satellites Observe "Traffic Jams" in Antarctic Ice Stream Caused by Tides

illconsidered — Tue, 03 Jan 2017 14:20:43 +0000

Satellites Observe "Traffic Jams" in Antarctic Ice Stream Caused by Tides

A fascinating press release I want to pass along. At first I thought it was maybe good news in that rising sea levels would slow glacier drainage into the oceans but the affect is the opposite:

For the first time, researchers have closely observed how the ocean's tides can speed up or slow down the speed of glacial movement in Antarctica. The new data will help modelers better predict how glaciers will respond to rising sea levels.

Caltech's Brent Minchew (PhD '16) and Mark Simons, along with their collaborators and in cooperation with the Italian Space Agency (ASI), exploited four COSMO-SkyMed radar-imaging satellites on the Rutford Ice Stream in Antarctica. The satellites gathered near-continuous data for nearly nine months from a variety of angles.

The Rutford Ice Stream is a fast-moving river of ice, approximately 300 kilometers long and 25 kilometers wide, in West Antarctica. It connects glaciers in the Ellsworth Mountains to the Filchner-Ronne Ice Shelf, a floating chunk of ice roughly the size of California. Driven by its own weight, the stream of solid ice flows downhill toward the sea at a rate of about one meter per day, though that speed varies by as much as 20 percent with the tides.

The variability is driven by the ice's interactions with the ocean. At low tide, the floating ice sinks far enough to ground out on the sea floor like a foundering ship, causing an ice traffic jam that can be detected up to 100 kilometers upstream. When the tide rises again, the ice lifts off of the sea floor and flows freely once more.

"A rising tide lifts all ships, and it also lifts all ice," says Minchew, a PhD student at Caltech while conducting the research and now a postdoctoral researcher the British Antarctic Survey. Minchew is the lead author of a paper about the study that was published by the Journal of Geophysical Research on November 22.

The ice stream was so sensitive to the change in tides that Simons and Minchew could detect the individual influences of solar and lunar tides.

The planet's solar and lunar tides are caused by the tug of the sun and the moon, respectively, on the earth. High tide occurs simultaneously on the sides of the earth facing toward and away from the sun and the moon because their gravitational pulls create a bulge, or high tide, in the planet.

The lunar and solar tides are not perfectly in sync: the lunar tide cycles from high to low every 12-and-a-half hours, while the solar tide cycles every 12 hours. When those two cycles align perfectly, the sea experiences its strongest tides. When they are most misaligned, the sea experiences its weakest tides.

Previous efforts to explore the effect of the tide on glacial movement relied on placing a GPS device directly on the ice. This technique, however, provides information for only one point of movement.

The Caltech team instead collected pairs of images taken from the same location in space but at different times, thus showing movement not just of a single point but continuous tracking of every single square inch of the surface of the ice streams. (Ice does not move as one solid fixed mass, but rather it flows like an incredibly viscous syrup—its motion is often likened to that of cold honey. As such, the movement of one point provides only the most basic information about the entire glacier.) Further, the variety of viewing angles provided by the constellation of satellites offered three-dimensional information about the ice's movement and revealed, for example, that the floating ice shelf moved more quickly, thus showing that the grounding effect was indeed responsible for changes in the ice's speed.

Studies on glacial movement could yield important data for scientists looking to model how glaciers will respond to the effects of climate change.

"The response of ice flow to changes in sea level and ocean temperature has a direct impact on contemporary sea-level rise," says Simons, professor of geophysics at Caltech. "Quantifying this is critical for understanding how Antarctica will evolve over the next decades and centuries as the climate warms and the marine-terminating glaciers are exposed to warmer ocean water."

With warmer water and high sea levels, glaciers will flow faster into the sea, melting more quickly once they reach the water.

Already, the study has yielded surprising information about the strength of ice and its ability to resist deforming due to glacial stress. As it turns out, ice is weaker along the margins of flowing glacial streams than previously suspected. The same technology and technique could be used to study the motion of glaciers worldwide, Minchew says.

Simons and Minchew collaborated with Caltech alumnus Bryan Riel (PhD '14) and Pietro Milillo of the University of Basilicata in Italy, both of whom are now affiliated with JPL.

The paper, titled "Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations," can be found online at http://resolver.caltech.edu/CaltechAUTHORS:20161123-141844145. This research was funded by NASA, the National Science Foundation, the Albert Parvin Foundation, and the Achievement Rewards for College Scientists (ARCS) Foundation.

Image: Horizontal motion of Ice Stream. As the tide falls, the floating Filchner-Ronne Ice Shelf grounds out, slowing down the progress of the Rutford Ice Stream. When the tide rises, the ice shelf floats again, allowing the flow of the ice stream to speed up. (B. Minchew/Caltech)

illconsidered Tue, 01/03/2017 - 09:20

The Earth is Not Moving

illconsidered — Mon, 25 Jul 2016 07:45:15 +0000

The Earth is Not Moving

"In order to save the dying heliocentric theory from the conclusive geocentric experiments performed by Michelson, Morley, Gale, Sagnac, Kantor and others, establishment master-mind Albert Einstein created his Special Theory of Relativity which in one philosophical swoop banished the absolute aether/firmament from scientific study and replaced it with a form of relativism which allowed for heliocentricism and geocentricism to hold equal merit. If there is no universal aetheric medium within which all things exist, then philosophically one can postulate complete relativism with regard to the movement of two objects (such as the Earth and sun). Nowadays, just like the theory of heliocentricism, Einstein's theory of relativity is accepted worldwide as gospel truth, even though he himself admitted geocentricism is equally justifiable"

Source: The Atlantean Conspiracy: The Earth is Not Moving

Offered for your reading pleasure. It is a master-stroke how a clerk working at the post office [update: er..patent office] is described as "establishment master-mind"! I really wonder how individuals can be intelligent enough to write at this level and yet believe in such nonsense.

But at the risk of making this post actually useful maybe someone can answer the question my googling was trying to answer before the article above distracted me: does Google Earth compensate for dimensional distortions due to satellite perspective?

illconsidered Mon, 07/25/2016 - 03:45

2015 Was the Hottest Year on Record by a Long Shot

illconsidered — Fri, 29 Jan 2016 13:58:50 +0000

2015 Was the Hottest Year on Record by a Long Shot

An illustrative graphic from Bloomberg.com arrived in my inbox. As they put it: "We just obliterated another heat record."

To view it, you'll have to head over to here: 2015 Was the Hottest Year on Record by a Long Shot

illconsidered Fri, 01/29/2016 - 08:58

Unmoderated Post on Moderation

illconsidered — Wed, 20 Jan 2016 09:31:14 +0000

Unmoderated Post on Moderation

I will allow comments through by default for repeat commenters again, first time commenters will still need an initial approval.

I will however now be a more active moderator and delete things that are useless or unnecessarily personal from now on, except on this thread.

This is unavoidably subjective but I will try to err on the side of permissiveness. The goal will be controlling the tone more so than the content. Readers should keep in mind the fact I am in an Australian time zone, so doomed comments may be visible for many hours. I expect this blog will remain pretty quiet for the time being, though I still hope to have more to say in the future. It is in some ways an interesting time in The Climate Wars (really wild weather, new global anomaly records, politics), but also in other ways it is all so much "same as it ever was".

illconsidered Wed, 01/20/2016 - 04:31

Global Day of Overshoot

illconsidered — Mon, 24 Aug 2015 19:36:15 +0000

Global Day of Overshoot

August 13th was Earth Overshoot Day. The correct date, if calculated precisely, would come earlier and earlier each year, the current choice is just an approximation.

This year, the year 2015, by sometime around August 13th, humanity had consumed as much of what we require from the lands and seas as our planet can sustainabley provide in an entire year. That is another way of expressing the fact that at current consumption rates, humanity requires 1.6 planet earth's worth of fruits and vegetables, meat, fish, wood and other organic materials. It is a remarkable annual deficit, and if it is not reduced to zero, we will simply run out of things vital to our survival. That is the simple arithmetic of "unsustainable".

But what does "unsustainable" look like?

Overdevelopment, Overpopulation, Overshoot by Tom Butler, William Ryerson, et al (Goff Books, March 2015)

One of the (very few) perks of blogging is the occasional free book offer that comes to my inbox. I don't often take advantage of them mostly just because of personal disinterest in whatever specific topic is at hand. Out of those offers that are interesting to me, I have to be realistic about what I am going to have time to read. An offer came to me a while ago that finally ticked those boxes. It was about an interesting, if bleak, subject: the mark humans have made on this planet through overpopulation and over consumption, and it was promising to be readable without a large time commitment since it was primarily a book of photography. I'm talking about the extraordinary book, Overdevelopment, Overpopulation, Overshoot by Tom Butler, William Ryerson, et al published by Goff Books, March 2015.

Because of this promotional book, I can show you, in the most graphic manner you might want, the answer to my rhetorical question above: what does unsustainable look like? The book is filled with high quality images from around the world. Images "framed with essays by renowned women’s rights, population and conservation experts," images that illuminate "the depth of the damage that human numbers and behavior have caused to the Earth — and which threaten humanity’s future prosperity."* Some of these images are awe-inspiring, some rather horrifying, but almost all of them are disturbingly compelling. Below are some examples reproduced here with permission of the publisher. I recommend buying the book and seeing them all.

Images are linked to higher resolution versions, please click.

Air pollution, C02, and water vapor rise from the stacks at a coal-burning power plant in the U.K.; © Jason Hawkes.

Tar sands-related tailings ponds are among the largest toxic impoundments on Earth and lie in unlined dykes mere meters from the Athabasca River; indigenous communities downstream are fearful of being poisoned by toxic seepage into the food chain. Alberta, Canada; © Garth Lentz.

Trucks the size of a house look like tiny toys as they rumble along massive roads in a section of a mine. The largest of their kind, these 400 ton capacity dump trucks are 47.5" long, 32.5" wide, and 25" high. Within their dimensions you could build a 3000 square foot home. The scale of the Tar Sands is truly unfathomable. Alberta Energy has reported that the landscape being industrialized by rapid Tar Sands development could easily accommodate one Florida, two New Brunswicks, four Vancouvers, and four Vancouver Islands.

On Midway Island, far from the centers of world commerce, an albatross, dead from ingesting too much plastic, decays on the beach; it is a common sight on the remote island. © Chris Jordan.

Indonesian surfer Dede Surinaya catches a wave in a remote but garbage-covered bay on Java, Indonesia, the world’s most populated island; © Zak Noyle.

Sprawling Mexico City, Mexico, population 20 million, density 24,600/square mile (9,610/square kilometer), rolls across the landscape, displacing every scrap of natural habitat; © Pablo Lopez Luz.

“American suburbia represents the greatest misallocation of resources in the history of the world. the far-flung housing subdivisions, commercial highway strips, big-box stores, and all the other furnishings and accessories of extreme car dependence will function poorly, if at all, in an oil-scarce future.” —James Howard Kunstler
Los Angeles, California, population 15 million typifies America’s consumption-oriented and car-dependent culture; © Mike Hedge.

Suburban Sprawl: “Human agriculture and industry are embedded in and supported by the natural ecosystems of earth.... Yet modern societies heedlessly displace, poison, overharvest, and directly assault natural ecosystems with little thought for their importance in their own sustenance.” —Paul and Anne Ehrlich aerial view of landscape outside Miami, Florida, shows 13 golf courses amongst track homes on the edge of the Everglades; Google Earth/NOAA, U.S. Navy, NGA, GEBCO.

To give a better sense of what you are looking at just above, right below is a full resolution enlargement of a small section from the center of this image:

Detail from Suburban Sprawl: Google Earth/NOAA, U.S. Navy, NGA, GEBCO.

Delhi Grid: “Humans evolved in wild nature. Only relatively recently in our time on Earth, roughly ten to twelve millennia ago, did we begin to domesticate other species—and ourselves. That first agricultural revolution set humanity on a trajectory of population growth and settlement-based land use. Increased social organization and the invention of cities went hand in hand to allow development of increasingly complex economic and political systems. In 2008, for the first time in history, the majority of humans on Earth lived in cities. We had become, at least superficially, urban animals.”Aerial view of New Delhi, India, population 22 million, density 30,000 per square mile (11,700/km2); Google Earth/2014 Digital Globe.

As with the image of Florida, below is a full-resolution enlargement of a small section from the center-bottom portion of the New Delhi image above:

Delhi Grid: Detail from center, bottom of Aerial view of New Delhi, India, population 22 million, density 30,000 per square mile (77,700/km2); Google Earth/2014 Digital Globe.

Megalopolis: Shanghai, China, a sprawling megacity of 24 Million; © Mike Hedge.

“I don’t understand why when we destroy something created by man we call it vandalism, but when we destroy something created by nature we call it progress.” —Ed Begley, Jr.
Depleting oil fields are yet another symptom of ecological overshoot; Kern River Oil Field, California, U.S.; © Mark Gamba/Corbis.

Cattle gather near a watering pond as fires set to clear and rejuvenate the land burn on a ranch in Sao Felix Do Xingu Municipality, Para State, Brazil, Aug. 12, 2008.
Daniel Beltra/Greenpeace

Cattle ranch in Agua Boa, Mato Grosso, Brazil, August 8, 2008.
Daniel Beltra/Greenpeace

Desolate landscape of working oil pumps on the Kern River Oil Field --- Image by © Mark Gamba/Gallery Stock/Galeries/Corbis

Sometimes called the Brazil of the North, Canada has not been kind to its native forests. Image of clear-cut logging on Vancouver Island, © Garth Lentz.

Views of the PSA container port in Singapore, the world's largest and busiest port in the world.

* Quotes borrowed from some of the promotional materials that came with the book offer.

illconsidered Mon, 08/24/2015 - 15:36

AFTIC Status Report

illconsidered — Wed, 19 Aug 2015 08:09:17 +0000

AFTIC Status Report

A gentle reader recently asked for a "status of the blog" report. As the two week delay between ask and answer can attest to, things are rather slow moving around here at the moment and I am mainly just my own lurker. I do have some new content that I will offer very shortly and a post or two in the slow cooker.

I guess in general I have been feeling like I have over the years said what I needed to say and was now only repeating myself. This is despite quite a few interesting developments over the past year ranging from juicy insider-blog gossip to political theatre to remarkable developments in climatology, both research and events.

I also realized that I was no longer being the example I intended in terms of How to Talk to a Climate Sceptic(tm). The key things I believe one must do/remember are:

Don't get personal
Remain infinitely patient
Always write for the lurkers, not the current antagonist

I have slipped on all of those points.

I have also been wrestling with determining the best comment policy for this blog (there is no one size fits all such policy). I have always taken a very hands-off approach and though I have been questioning that, I have not convinced myself there is clearly a better one.

Anyway, that is just some personal stream of consciousness stuff triggered by the above mentioned "what's up?" comment. I'm happy to hear updates from formerly regular posters/lurkers here as well...what blogs to you spend time on? Are there topics you'd like to see covered? Maybe there is a guest post someone has to offer -being on Science Blogs seems to guarantee at least a few hundred hits/day when content goes up. Feel free to post some thoughts below.

As I said I really will have a post in the next few days and hope I have remained in a few RSS feeds.

illconsidered Wed, 08/19/2015 - 04:09

Cat out of the Bag

illconsidered — Mon, 13 Apr 2015 07:37:18 +0000

Cat out of the Bag

I haven't seen this making the climate blog rounds (though I don't pay as close attention anymore as I used to...) so I thought supporters of science and detractors alike might like to know that the cat is out of the bag and the Global Warming Hoax has been exposed.

See below:

Continental drift and evolution surely fall into that that same mix.

illconsidered Mon, 04/13/2015 - 03:37

Happy New Year!

illconsidered — Fri, 02 Jan 2015 09:45:36 +0000

Happy New Year!

Other original images can be viewed here. (No, they are not New Year's, but they are fireworks!)

illconsidered Fri, 01/02/2015 - 04:45

Happy Holidays!

illconsidered — Thu, 25 Dec 2014 20:13:00 +0000

Happy Holidays!

Sorry, I don't know who to credit for that, I got it from a Facebook post...

illconsidered Thu, 12/25/2014 - 15:13

As alien as it gets

illconsidered — Fri, 14 Nov 2014 02:20:08 +0000

As alien as it gets

Humankind has touched the surface of the solar system's most alien of objects.

Image taken from NAVCAM top 10 at 10 km – 10.

There are no words...

illconsidered Thu, 11/13/2014 - 21:20