“Does it get better than this?” U.S. flag and Denali

August 10, 2012

Instagram from the Department of Interior, yesterday:

U.S. flag and Denali on an almost-clear day; Department of Interior photo, August 2012 - public domain

U.S. flag and Denali on an almost-clear day; Department of Interior photo, August 2012 – public domain

usinterior Tweeted, “Does it get any better than this?”

Denali, also known as Mt. McKinley, is the highest point in North America, 20,320 feet (6,194 m) above sea level.  Measured base to peak, it’s the tallest mountain on land on Earth — Everest and other Himilayan peaks rise from a very high plateau.  Denali is high enough that it makes its own weather.  Finding a day when the mountain is not almost completely obscured by clouds is rare, locals say.  Finding an almost-clear view, with blue sky in the background, is a cause for photographer excitement.

You’ll notice straight-line clouds in the sky — condensation trails from passenger jets.  I wonder how many flights bend a little to get a better view of the mountain for passengers?  Do big airlines even do that anymore?

Nice shot.  I could learn to like Instagram with more photos of this quality.

Better, it would be nice to be there, taking these shots.

More, including the controversy over the mountain’s name:


Big bone sale in Dallas, part 2: Is P. Z. Myers bidding on this one?

June 12, 2011

It’s perfect for him.  Perfect.  Bidding stands at about $2,500 at the moment:

Gem tektite octopus - Heritage Auctions June 12, 2011 - IMGP6864 - copyright Ed Darrell, use permitted with attribution

Did our cephalopod overlords leave this for us, 29 million years ago? It's looking right at you, you know.

Is P. Z. Myers bidding on this thing?

According to the catalogue from Heritage Auctions, this piece of glass was formed in what is now the Libyan Sahara 29 million years ago when a meteoroid struck the sand, creating massive heat that fused sand into glass.  This light lemonade colored glass comes from only a small part of the Libyan sands.  Tektite is collectible by itself.  Some craftsman (unidentified and unplaced in time by Heritage Auctions) carved this piece into a cephalopod.

Taking an uncommonly large and clear specimen, the master lapidarist has carved the form of a malevolent-looking octopus, with superb rugose skin texture and a mass of curling tentacles. With a gorgeous translucence and lovely delicate green/yellow color, this exceptional sculpture measures 2¾ x 2 x 1¾ inches. Estimate: $2,800 – $3,200.

Compared to the giant articulated dinosaurs about 50 feet away from the display, one could easily overlook this little gem.  Still, bidding online looked to be pretty active.  Is P.Z. still in the British Isles?  Is he bidding by internet?  Is his Trophy Wife™ planning a Father’s Day surprise?

Tektites should pique your interest, Dear Reader.  Glass formed only when interplanetary objects smash into the planet, providing clues to the makeup of our solar system and universe, dating back well before recorded time, found in only a few fields around the Earth.  They are the perfect marriage-merger of geology, astronomy, geography, natural history, history and, in this case, art.   They are popular among collectors.    Who walks away with this one this afternoon?


Big bone sale in Dallas

June 11, 2011

Big bones.  Big sale.

Heritage Auction's triceratops, for Jun 12, 2011 auction

Triceratops welcomes bidders and gawkers to the Heritage Auction sale of fossils, gems, meteorites, and other national history ephemera. HA estimates this nearly-complete triceratops, mounted, to be worth about $700,000; less than 24 hours before the live auction, it has an online bid of $500,000 already.

Heritage Auctions set up a bug bunch of fossils, gems, meteorites, taxidermy, and art work from natural materials, for an auction on Sunday, June 12, 2011.

2011 June Dallas Signature Platinum Natural History Auction – Dallas, TX.  Auction #6061.

I can’t afford to bid, but they let me in to get photos.  Nice people.

Heritage Auctions' June special, a triceratops - IMGP6882 photo by Ed Darrell; use permitted with attribution

Heritage Auctions' June special, a triceratops - photo by Ed Darrell; use permitted with attribution

The triceratops greets visitors and bidders at the display site, the Tower Building at Dallas’s art deco gem, Fair Park.  (If you look at the ceiling above the triceratops, you can see where restorers have stripped away several layers of paint to reveal the original ceiling paintings — original artwork, including murals, was painted over in the years following the dramatic debut of the buildings; restoration work proceeds slowly because of lack of funding.)

Triceratops horridus
Cretaceous
Hell Creek formation, Harding County, South Dakota

Researchers dug this particular specimen out of the ground in 2004.  HA’s description just makes one’s science juices flow:

Triceratops has enjoyed much cultural publicity ever since its discovery. It is an iconic dinosaur that has appeared in movies ranging from black and white cinema to modern movies like “Jurassic Park.” It has also been in cartoons, such as the children’s classic “The Land before Time.” Triceratops is also the official state fossil of South Dakota and the official state dinosaur of Wyoming.

The present specimen was discovered in 2004 in two parts: First, the fossil hunters came upon pieces of dinosaur bone eroding down a gully. Following these bone fragments, they eventually came upon large bones that would indicate the presence of a large Ceratopsian dinosaur. While this large mass of bones was being excavated, other members of the team followed another bone trail which led them to an amazingly well preserved skull 750 feet away from the original discovery. Over the course of months, the specimens were carefully excavated in large blocks; each specimen was covered in plaster jackets and removed from the field to the lab. It was only during preparation that they discovered the dinosaur was a Triceratops, and it happened to be a Triceratops with an incredibly complete skull. The bones and skull were carefully removed from their field jackets and prepared using hand tools. Broken bones were professionally repaired and restored while a few missing elements were cast from other Triceratops skeletons. A custom made mount was created to support the bones and the skull; innovative bracket mounts were crafted for each bone so that no bones had to be damaged in order to mount them. The bones were mounted in osteologically correct position; making it comparable to and possibly surpassing the accuracy of older mounts in museum displays. Though it is impossible to say whether or not the skull is original to the specimen, being discovered 750 feet apart, it is certainly possible that the two elements are associated for a number of reasons: first, the size of the skull is consistent with the proportional size dimensions of the skeleton, and second, the surrounding matrix (host rock) was identical in composition.

The completed skeleton is enormous; measuring 19 feet long from head to tail, 11 feet across, and towering 12 feet tall. The skull itself measures 7 feet long with 3 ½ foot long horns; placing it near the top of the size range for Triceratops skulls. The leg bones stand 10 feet tall from toes to the top of the scapula; dwarfing many other Triceratops skeletons. Given that the skull represents about 30% of a dinosaur’s entire skeleton, the present specimen is about 75% original bone, with the right leg, pelvic region, several cervical vertebrae and a few tail vertebrae being cast reproductions.

Who owns the thing?  Who put it together?   Who is losing the specimen, should it go to a private collection (you got a living room that big?), and which museum really wants it?

But that’s just one of the specimens up for sale at this auction, and not necessarily the best.  Also up for bid:  A stegosaurus, and an allosaurus, posed as a “fighting pair.”

Fighting pair - allosaurus and stegosaurus, from Heritage Auctions' June 12, 2011 sale of fossils IMGP6839 - photo copyright by Ed Darrell, use permitted with attribution

The "fighting pair," an allosaurus (left) and stegosaurus (right) posed in combat positions. Photo by Ed Darrell, use permitted with attribution.

If it sells, the stegosaurus will cost a lucky bidder more than $1 million.  The allosaurus requires $1.6 million.

Am I jaded?  On the one hand you can’t look at these specimens without thinking they deserve to be seen by kids, and adults, and studied by paleontologists and biologist of all stripes — and so who has the right to sell these off?  On the other hand, this is a Second Gilded Age, and the search for prize fossil specimens is often financed by the proceeds from these auctions.  I enjoyed an hour’s browsing and photographing — a slide presentation on the wonders of America for some sleepy class next fall.

How many of these specimens will I get a chance to see again in the future?

Or, Dear Reader, how many of these will you ever get a chance to see?

HA will sell a lot more than just a few dinosaur fossils.  This same sale includes the largest shark jawbone ever found, stuffed Kodiak and polar bears (from the same hunter), gems, art from petrified wood and fossilized fish, and a large selection of meteorites, including the only meteoroid ever confirmed to have struck and killed a living creature (a cow in Argentine; you can’t toss a stone without hitting a cow in Argentina, I hear).

Giant shark jaw for Heritage Auctions' June 2011 sale

Requires a large wall and high ceilings to display

I don’t plan to go bid; there’s about an hour remaining for online bidding tonight, but if you’re interested and you’ve got your income tax refund burning a hole in your pocket, you can also bid by telephone and hotlink on the internet (go to the Heritage Auction site for details).   Frankly, I don’t think the sale will get the attention it deserves.  I hope these spectacular specimens will land where they can get  a great, admiring and studious audience.


Yellowstone, Land to Life — a film to free from bondage

March 20, 2011

Yes, it’s a tease.  Drat.  Just a trailer for the film.

But how exquisite is just the trailer!

Yellowstone National Park Orientation Film (excerpt) from Northern Light Productions on Vimeo.

Northern Light Productions made the film for the “Canyon Visitor Education Center in Yellowstone National Park. The film offers a compelling overview of the ‘big picture’ geology that has shaped and continues to influence Yellowstone and its ecosystem.”

Big picture geology?  How about making this film available to schools to talk about geology, geography, and history?

Yellowstone National Park annually gets about three million visitors.  Yellowstone is one of those places that ever American should see — but at that rate, it would be more than 100 years before everybody gets there.

We need good, beautifully shot, well-produced, interesting films on American landmarks in the classroom.

How do we get this one freed for America’s kids, Yellowstone Park?


Laden’s late; but, is Yellowstone gonna blow AND TAKE US WITH IT?

February 26, 2011

The veteran reader of this blog — can there be more than one? — may recall the kerfuffle a couple of years ago when there was a “swarm” of earthquakes in the Yellowstone.  Alas for those prone to panic attacks, the swarm ran through the Hanukkah/Ramadan/Christmas/KWANZAA/New Year’s holidays, when other news is slack.

Yellowstone Caldera, Smith and Siegel 2000

What the Yellowstone Caldera might look like from space, by moonlight, on a clear night, if you can imagine the borders of Yellowstone National Park very vividly - Smith and Siegel, 2000

You might understand, then, why I say Greg Laden turns his considerable story-telling prowess to the issue late.  Still, his prowess towers over the rest of us, and he tells a great story.

Is the Yellowstone safe? he asks, rhetorically.

The answer is complex:

1) Wear a seat belt when driving around in the region;

2) Don’t feed the bears and make sure you understand bear safety; and

3) Somebody is going to get blasted by some kind of volcano in the area some day, but even if you live there the chances are it won’t be you.

The joy is in the journey — go read Laden’s explanation of the rising lava.  Heck, even those of us who think we know that stuff understand it better when he explains it.

Earlier in the Bathtub:

Also see:


American Icons: Half Dome in Yosemite National Park

February 2, 2011

One of what should be an occasional series of posts on American iconic places, natural features, sights to see, etc.  For studies of U.S. history and U.S. geography, each of these posts covers subjects an educated American should know.  What is the value of these icons?  Individually and collectively, our preservation of them may do nothing at all for the defense of our nation.  But individually and collectively, they help make our nation worth defending.

This is a less-than-10-minute video you can insert into class as a bell ringer, or at the end of a class, or as part of a study of geologic formations, or in any of a number of other ways.  Yosemite Nature Notes provides glorious pictures and good information about Yosemite National Park — this video explains the modern incarnation of Half Dome, an enormous chunk of granite that captures the imagination of every living, breathing soul who ever sees it.

Potential questions for class discussion:

  • Have you put climbing Half Dome on your bucket list yet?  Why not?
  • Is it really wilderness when so many people go there?
  • How should the National Park Service, and the Forest Service and Bureau of Land Management, manage these spectacular, completely unique features, both to preserve their wild nature, and allow people to visit them?
  • What are the federalism issues involved in protecting Half Dome, or any grand feature, like the Great Smokey Mountains, Great Dismal Swamp, Big Bend, Yellowstone Falls, or Lincoln Memorial?
  • Does this feature make you wonder about how glaciers carve mountains and valleys?  (Maybe you should watch this video about glaciers in Yosemite.)
  • What is the history of the preservation of the Yosemite Valley?
  • Planning your trip to Yosemite:  Which large city airports might be convenient to fly to?  (What part of which state is this in?)
  • What other grand sights are there to see on your trip to Yosemite?
  • What does this image make you think?  Can you identify the people in it?

    John Muir and Teddy Roosevelt in Yosemite Valley

    Who are those guys? Why might it matter? (Answer below the fold)

  • How about this image? Who made this, and so what?

    Albert Bierstadt, Sunrise, Yosemite Valley, ca. 1870 - Amon Carter Museum, Fort Worth, Texas

    Photo or painting? Where could you see this work?

Read the rest of this entry »


Debunking creationist claims of human and dinosaur footprints together . . .

September 26, 2010

. . . from 1983!

Steve Schafersman, now president of Texas Citizens for Science, played the yeoman then:

Description of the program:

Did humans coexist with dinosaurs? The tracks tell the tale. Dr. John R. Cole, Dr. Steven Schafersman, Dr. Laurie Godfrey, Dr. Ronnie Hastings, Lee Mansfield, and other scientists examine the claims and the evidence. Air date: 1983.

Tip of the old scrub brush to the National Center for Science Education.


Volcanoes, travel plans, and history

June 13, 2010

James is home for the weekend, then back to Wisconsin on Sunday for a summer of physics beyond my current understanding.  He flew home to wish bon voyage to Kenny, who is off to Crete to learn how to teach English, and then (we hope) to find a position teaching English to non-English speakers somewhere in Europe.

I wondered:  What about that volcano erupting in Iceland?

Little worry for the trip over, this weekend.  Longer term?

So I turned to the Smithsonian to find a volcano expert, and came up with this video of  Smithsonian Geologist Liz Cottrell who explains where the eruption of Eyjafjallajökull fits in history, and maybe some — with a lesson in how to pronounce Eyjafjallajökull’s name.

So:

  1. Can teachers figure out how to use this in geography, and in world history?  (Science teachers, you’re on your own.)
  2. Life is a gamble if you live close to a volcano, and sometimes when just happen to be downwind.
  3. In the past couple of hundred years, maybe volcanoes worldwide have been unusually quiet.
  4. As to size of eruptions and the damage potential:  We ain’t seen nothin’ recently!

Tip of the old scrub brush to Eruptions!


Nature vs. Industrial Light and Magic

April 20, 2010

Nature wins.  You can’t dream up effects like this.

From Astronomy Picture of the Day (APOD), a photo of Iceland’s latest fuming, smoking European nightmare.  Wow.  Just wow.

Ash and Lightning Above an Icelandic Volcano Credit & Copyright: Marco Fulle (Stromboli Online)

Ash and Lightning Above Eyjafjallajökull, an Icelandic Volcano - Credit & Copyright: Marco Fulle (Stromboli Online)

How did Marco Fulle of the Stromboli team of volcano observers get that photograph?  More of his great photos, here.

More:

Tip of the old scrub brush to Gormogons.


You’re not using this technology in your classroom?

April 12, 2010

Here’s another opportunity to put real, cutting edge technology in your classroom.  In fact, your kids could probably invent all sorts of new uses for it.

Have you even heard of this stuff?  Can you use it, live, with the equipment you’ve got?

Blaise Aguera y Arcas  of MicroSoft demonstrated augmented-reality maps using the power of Bing maps, Flickr, Worldwide Telescope, Video overlays and Photosynth, to an appreciative and wowed audience at TEDS:

My prediction:  One more advance in computer technology that classrooms will not see in a timely or useful manner.

But have you figured out how to use this stuff in your geography, history, economics or government classes?  Please tell us about it in comments. Give examples and links, please.


Mexico earthquake: What do we know?

April 5, 2010

Baja California — that’s in Mexico, you European readers — got hit with a large earthquake tonight, a 7.2 on the logarithmic Richter Scale according to some early reports. At least one person died; Mexicali, on the border with California, reports many people trapped.  A state of emergency has been declared.

BBC gives the facts:

A 7.2 magnitude earthquake has hit the Mexican peninsula of Baja California, killing at least one person and causing tremors as far away as Nevada.

The quake struck at 1540 (2240 GMT), 26km (16 miles) south-west of Guadalupe Victoria in Baja California, at a depth of 32km, said the US Geological Survey.

Some people are still trapped in their homes in the city of Mexicali, where a state of emergency has been declared.

It was the worst quake to hit the region for many years, officials said.

The US Geological Survey said some 20 million people felt tremors from the largest quake to hit the area since 1992.

My students with Mexico connections tend to come from farther east, and higher in the mountains — I don’t think I have a single student who visits Baja California on breaks.  But the news will prompt questions from them tomorrow.

The U.S. Geological Survey (USGS) tracks earthquakes around the world.  It should have solid information.  Data on the April 4 7.2 quake are here.

Here’s the tectonic summary:

A magnitude 7.2 earthquake occurred at 3:40:40 p.m. (local time at the epicenter) on Sunday, 4 April 2010 in Baja California, approximately 75 km south of the Mexico-USA border. The earthquake occurred at shallow depth (approximately 10 km) along the boundary zone between the North American and Pacific plates. Since earthquakes have been recorded instrumentally, only two similar sized earthquakes have been recorded in the area. The first was the 1892 earthquake estimated at magnitude 7.0-7.2 along the Laguna Salada fault just south of the USA-Mexico border. The second was the 1940 Imperial Valley magnitude 6.9 earthquake which occurred in southernmost California. Today’s event is located nearly in line with these earthquakes along the plate boundary, but is situated farther to the south. There are several active faults in the vicinity of today’s earthquake, and the particular fault that generated this quake has not yet been determined. Faulting is complex in this region, because the plate boundary is transitional between the ridge-transform system in the Gulf of California and the continental transform system in the Salton Trough. Most of the major active faults are right-lateral strike-slip faults with a northwest-southeast orientation, similar in style to the San Andreas fault to the north. Other faults in the vicinity with the same orientation include the Cerro Prieto fault and the Laguna Salada fault.

USGS hosts good maps, too, like this “shake map” (click the map to go to the USGS site for more information):

USGS "shake map" for the April 4 7.2 quake near Mexicali, Mexico

USGS "shake map" for the April 4 7.2 quake near Mexicali, Mexico - Click to go to USGS site

What other questions can we anticipate?  Somebody will ask whether this quake is related to the Haiti and Chilean quakes (probably not closely related).  Somebody will wonder about the Pacific Ring of Fire, and this quake’s relation to volcanoes and general earthquake activity around the Pacific (high relationship).  Someone will want to know about quakes in your area.  Is this the precursor to “the Big One?”

The USGS site is a good place to start on all of those questions.


Okalahoma earthquakes: No swarm

March 6, 2010

Three earthquakes in a week do not make a swarm.  Interesting that the last post on an earthquake in Oklahoma drew earthquake conspiratorialists and “skeptics.”  Too many people distrust all science and sources of information these days.

Here’s the dirt on Oklahoma’s shaking in the last week, from the U.S. Geological Service site:

Earthquake List for Map Centered at 36°N, 97°W

Update time = Sat Mar 6 18:00:02 UTC 2010

Here are the earthquakes in the Map Centered at 36°N, 97°W area, most recent at the top.
(Some early events may be obscured by later ones.)
Click on the underlined portion of an earthquake record in the list below for more information.

MAG UTC DATE-TIME
y/m/d h:m:s
LAT
deg
LON
deg
DEPTH
km
LOCATION
MAP 3.1 2010/03/05 20:35:13 35.608 -96.783 5.0 3 km ( 2 mi) E of Sparks, OK
MAP 2.5 2010/03/03 04:35:17 35.549 -97.282 5.0 2 km ( 1 mi) SSE of Jones, OK
MAP 4.1 2010/02/27 22:22:27 35.557 -96.747 3.3 9 km ( 5 mi) SE of Sparks, OK

This isn’t unusual at all, of course. I think many people just don’t understand that earthquakes happen all the time, but they usually get crowded out of the newspaper because no one really cares.

For contrast, take a look at this animated map of a strip a little wider than Utah, covering from north of the Yellowstone Caldera to Arizona.  Run the animation.  Generally on any day there will have been at least two dozen earthquakes in the previous week, several magnitude 3, occasionally a magnitude 4 thrown in.

Almost none of those quakes make any news.

Maybe it’s the Earth, laughing.  We can hope.

Laugh, and the world laughs with you;
Weep, and you weep alone.
For the sad old earth must borrow it’s mirth,
But has trouble enough of its own.
Sing, and the hills will answer;
Sigh, it is lost on the air.
The echoes bound to a joyful sound,
But shrink from voicing care.

(Excerpted from “Solitude,” 1917, by Ella Wheeler Wilcox (1850-1919))


Shakiest states — geologically, that is

March 4, 2010

USGS map of states with the most quakes

Quake rankings of states

Which states shake the most?  Here are the top 20.

Surprised that Maine makes the list?

Much more from the US Geological Survey here, “Top Earthquake States.”


Annals of global warming: Glaciological map of Antarctica’s Palmer Land Area, 1947-2009

March 3, 2010

Are the ice fields of Antarctica increasing or decreasing?  How do we know?

U.S. Geological Survey released a study of the change in glaciation in Antarctica between 1947 and 2009.  Serious student of climate change will heed what the maps show — better bookmark the site.  The study and publication were done in a joint effort of USGS, the British Antarctic Survey, the Scott Polar Research Institute, and the Bundesamt für Kartographie und Geodäsie (same page, in English, here).

Coastal-Change and Glaciological Map of the Palmer Land Area, Antarctica: 1947—2009

By Jane G. Ferrigno,1 Alison J. Cook,2 Amy M. Mathie,3 Richard S. Williams, Jr.,4 Charles Swithinbank,5 Kevin M. Foley,1 Adrian J. Fox,2 Janet W. Thomson,6  and Jörn Sievers

Introduction

Cover of USGS publication, Coastal-Change and Glaciological Map of the Palmer Land Area, Antarctica: 1947—2009

Cover of USGS publication, Coastal-Change and Glaciological Map of the Palmer Land Area, Antarctica: 1947—2009

Reduction in the area and volume of the two polar ice sheets is intricately linked to changes in global climate, and the resulting rise in sea level could severely impact the densely populated coastal regions on Earth. Antarctica is Earth’s largest reservoir of glacial ice. Melting of the West Antarctic part alone of the Antarctic ice sheet would cause a sea-level rise of approximately 6 meters (m), and the potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be 65 m (Lythe and others, 2001) to 73 m (Williams and Hall, 1993). The mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is highly complex, responding differently to different climatic and other conditions in each region (Vaughan, 2005). In a review paper, Rignot and Thomas (2002) concluded that the West Antarctic ice sheet is probably becoming thinner overall; although it is known to be thickening in the west, it is thinning in the north. The mass balance of the East Antarctic ice sheet is thought by Davis and others (2005) to be positive on the basis of the change in satellite-altimetry measurements made between 1992 and 2003.

Measurement of changes in area and mass balance of the Antarctic ice sheet was given a very high priority in recommendations by the Polar Research Board of the National Research Council (1986), in subsequent recommendations by the Scientific Committee on Antarctic Research (SCAR) (1989, 1993), and by the National Science Foundation’s (1990) Division of Polar Programs. On the basis of these recommendations, the U.S. Geological Survey (USGS) decided that the archive of early 1970s Landsat 1, 2, and 3 Multispectral Scanner (MSS) images of Antarctica and the subsequent repeat coverage made possible with Landsat and other satellite images provided an excellent means of documenting changes in the cryospheric coastline of Antarctica (Ferrigno and Gould, 1987). The availability of this information provided the impetus for carrying out a comprehensive analysis of the glaciological features of the coastal regions and changes in ice fronts of Antarctica (Swithinbank, 1988; Williams and Ferrigno, 1988). The project was later modified to include Landsat 4 and 5 MSS and Thematic Mapper (TM) images (and in some areas Landsat 7 Enhanced Thematic Mapper Plus (ETM+) images), RADARSAT images, aerial photography, and other data where available, to compare changes that occurred during a 20- to 25- or 30-year time interval (or longer where data were available, as in the Antarctic Peninsula). The results of the analysis are being used to produce a digital database and a series of USGS Geologic Investigations Series Maps (I-2600) (Williams and others, 1995; Swithinbank and others, 2003a,b, 2004; Ferrigno and others, 2002, 2005, 2006, 2007, 2008, and in press; and Williams and Ferrigno, 2005) (available online at http://www.glaciers.er.usgs.gov).

The paper version of this map is available for purchase from the USGS Store.

What’s the condition of glaciers in Antarctica?  Now you can look it up.

The pamphlet accompanying the maps says under “Discussion”:

The most noticeable and dramatic changes that can be seen on the Palmer Land area map are the retreat of George VI, Wilkins, Bach, and northern Stange Ice Shelves. The northern ice front of George VI Ice Shelf was at its farthest extent during our period of observation between 1966 and 1974. It retreated, losing 906 km2 between 1974 and 1992 and 87 km2 between 1992 and 1995. After 1995, it retreated an additional 1 km to more than 6 km by 2001. The southern George VI ice front retreated considerably from 1947 to the late 1960s. From the late 1960s to 1973, there was additional substantial retreat, the greatest during the period of measurements.  From 1973 to 2001, there was overall noticeable retreat.

Wilkins Ice Shelf had four ice fronts up till 2009; all retreated during the time period of our study, but Wilkins “a” and “b” have had the most dramatic change, including extensive calving in 2009 that eliminated ice front “b” and threatened the future of the ice shelf. During the period of observation, the Bach Ice Shelf front maintained a fairly consistent profile, and advanced or retreated at the same time along the entire ice front. The overall trend of Bach Ice Shelf is retreat. On the northern Stange Ice Shelf during the period of observation, the 1947, 1965–66, 1973, and 1986 ice fronts were more advanced, and the 1997 and 2001 ice fronts were more in retreat. However, the earlier data are less accurate geographically, and it is difficult to quantitatively analyze them. The later satellite images are more accurate, and it is possible to measure overall advance from 1986 to 1989, then retreat from 1989 to 1997 and from1997 to 2001; the net result was retreat.

The three coastal-change and glaciological maps of the Antarctic Peninsula (I–2600–A, –B, and –C) portray one of the most rapidly changing areas on Earth. The changes exhibited in the region are widely regarded as among the most profound and unambiguous examples of the effects of global warming yet seen on the planet.

Resources:


Free, detailed maps of Germany

March 3, 2010

Need maps of Germany for geography or world history?

Germany’s geodetic and cartography agency, Bundesamt für Kartographie und Geodäsie, in Frankfurt,  has three detailed maps available in .pdf form at it’s website.

These .pdfs are suitable for papers sizes roughtly 8.5 by 11 inches in the U.S. — but they probably would scale up nicely for poster-size maps, too.  The maps are in color, and in German.


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