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Repeat Photography
Posted on Wednesday, March 22, 2006 @ 4:02 pm by Dave Schumaker
Repeat photography for the analysis of geologic processes has been picking up quite a bit of steam in the past few years. The latest news is courtesy of this USGS press release, announcing a new website documenting the changes in Glacier National Park, Montana.
U.S. Geological Survey (USGS) scientists with the Global Change Research Project are unveiling a new website featuring a collection of repeat photographs of glaciers in and around Glacier National Park, Montana. The striking images created by pairing historical photographs with contemporary photographs reveal significant glacial recession.
[...]
USGS scientists began documenting glacial decline through photography in 1997. While less quantitative than other high-tech methods of recording glacial mass, depth, and rate of retreat, repeat photography provides an effective visual tool to better understand how climate change contributes to the dynamic landscape of Glacier National Park.
There are other areas repeat photography has been used in as well. A history of land use on the Colorado Plateau, photographs documenting vegetation change in Alaska (originally used to analyze structural geology and locate oil bearing rocks).
Now that I think about it, there are also 3 other research projects I know about that have used repeat photography (unfortunately I cannot find links to them). One of them is a comparison of areas immediately after the 1906 earthquake and now (fascinating photos actually), Tom Hanks with the USGS Menlo Park has used photographs his father took of the Colorado River and compared them with photographs taken recently, and a project I participated in mapping travertine dams along Fossil Creek in Arizona.
Discovering Asteroid Impacts from Home
Posted on Tuesday, March 21, 2006 @ 12:38 am by Dave Schumaker
I recently came across this story posted on March 6th that tells how a group at Astroseti.org used Google Earth to find promising signs of previously unknown impact craters on our planet. This is similar to the story of an Italian randomly using Google Earth last summer and finding the remains of an ancient Roman Villa in his hometown.
Emilio González used Google Earth to look at a recently discovered impact crater in the Sahara Desert. “I thought that logically the silhoute would be hard to appreciate and that would be the reason it took so much time to discover, but following the article guidelines I went directlt [sic] to Egypt/Libya border and in less than a minute I perfectly saw the structure.”
Curious to see if he could spot any similar structures in the desert, he began to have a look around. “Suddenly the questions came to me. No one saw this before? How can a 31 km diameter structure not be noticed? So I decided to explore around for a while to check for similar structures. Just passed the Libyan border entering Chad at 121 miles “flying” high when another circular structure appeared in my screen. A closer look was showing, apparently, a typical impact structure, not volcanic. Of course, finding an impact crater has no merit if it is an already known one, so I had to check and visited the Canadian Brunswick University impact crater database, in Canada, and none of the listed matched my discovery.”
His email correspondance with geologists yields some promising results, however no one can be sure until actual field work is done at the locations to examine physical evidence on the ground.
For those using Google Earth, you can download a KMZ file that will list roughly 170 impact craters located around Earth. Check it out.
Geology Related Software
Posted on Tuesday, March 21, 2006 @ 12:20 am by Dave Schumaker
One thing I’ve been interested in (for both curiousity’s sake, as well as practical applications) are geology related programs that run on my home computer. Here is a small list of mostly free/cheap programs that I have come across in my experience. Do you have any suggestions for programs or applications that should be added? Comment below and I’ll add them to this post!
Windows
- Earthquake3D - Nothing more than a simple application that brings up a wireframe globe of the Earth and downloads the last 7 days of earthquake information. Basically an application form of the USGS earthquake website.
- Google Earth - Runs under either Windows or OS X, while not neccesarily a geology program, it has been an interesting tool for looking at our planet in new ways. Whether looking up where you grew up or examining volcanoes and glaciers, Google Earth is a great tool.
- Stereonet - Free for academic use, this program allows you to plot and manipulate various data using stereonets. A very handy tool for structural geologists. Runs under both WinXP and OS X. Check the website for other geology related programs.
Mac OS X
- Google Earth - See above description.
- OSXGeolCalc - Another structural geology tool using stereonets. Other geology programs for OS X are available on the website.
- Stereonet - See above description.
Petroleum Deposits in Afghanistan
Posted on Thursday, March 16, 2006 @ 9:56 am by Dave Schumaker
A new report by the USGS documents undiscovered petroleum deposits in Northern Afghanistan. Specifically, the amount of petroleum beneath the surface may be much greater than originally expected. Compared to previous estimates, the current report shows 18 times more oil resources in Afghanistan than originally thought and 3 times more natural gas resources. It is a rather significant find.
On a similar note, Mexican officials announced the discovery of a new large oilfield earlier this week as well. The discovery rivals what is currently the largest producing oilfield in Mexico.
Of course, given today’s political climate and situations going on around the world, it leads some to raise an eyebrow at these estimates. One reader named Tony emailed me, “Forgive me, but I don’t trust anything the goverment says anymore. Is there some way to tell if this is legit instead of some ‘no global warming’ science?“
Fire and Brimstone: Parts I and II
Posted on Tuesday, March 7, 2006 @ 7:01 pm by Ron Schott
Recent geologic studies at two volcanoes notorious for devastating historical eruptions shed new light on the past and potential future effects on nearby civilizations.
Mount Vesuvius is famous for its eruption of 79 A.D. (as chronicled by Pliny the Younger) that wiped out the Roman cities of Pompeii and Herculaneum. Although modern Vesuvius looms above Naples, Italy (via Google Earth) it was not until a recent study of a prehistoric eruption from this mountain that the nature of the threat to this major metropolitan area was fully understood.
“There was this Bronze-Age eruption about 4,000 years ago, and then 2,000 years ago there was the AD 79 event. It seems that just about every 2,000 years, there’s been a major eruption of this scale at Vesuvius,” said Sheridan, who has studied all of the major eruptions at Vesuvius going back to the birth of the volcano 25,000 years ago.
Perhaps the most extraordinary finding was what the authors call “decisive proof of a massive exodus” from the area, demonstrated by the finding of thousands of human and animal footprints, embedded in the wet volcanic ash and leading away from the volcano.
In a second study, geologists led by Haraldur Sigurdsson have recently published the results of a combined archeological/geological excavation of the deposits of the 1815 eruption of Tambora on the island of Sumbawa in Indonesia.
The eruption of Mount Tambora on the Indonesian island of Sumbawa in 1815, the largest volcanic eruption in human history, killed 117,000 people and extinguished the tiny kingdom of Tambora. After 20 years of research, a scientist from the University of Rhode Island’s Graduate School of Oceanography has located the first remnants of a Tamboran village under 10 feet of ash and has unearthed the first clues about its culture.
“There’s potential that Tambora could be the Pompeii of the East, and it could be of great cultural interest,” said Sigurdsson, who believes the village includes a large wooden palace that he hopes to find on a future expedition. “All the people, their houses and culture are still encapsulated there as they were in 1815. It’s important that we keep that capsule intact and open it very carefully.”