GIS for Archaeology and CRM

Posted last week at the Onion, is a fantastic story of the discovery of a long lost technological marvel; an email from 1995! The archaeologists interpretation of this techno-fact is quite astute and well founded, in my opinion.

“Researchers were hoping that “Untitled 1995,” as they’ve dubbed it, would help fill-in the long-sought missing link between the ancient e-mail world and the modern era.”

The story is a good laugh, well worth the price of admission.

After learning that my RSS feed was broken for a long time (thanks Tijl), I implemented a new Feedburner feed. By clicking on the RSS icon on the right hand column, you can add my feed to your favorite aggregator. Alternately, if you are using FireFox/Mozilla, you can click on the same icon in the location bar of your browser and add it as a live bookmark.

To anyone who tried to subscribe before, sorry for the inconvenience.

Blogged at the CCA weblog on Tuesday is a link to a fantastic project undertaken by Dr. Ron Blakey.The maps created by Dr. Blakey represent time slices of the geologic transformations, via plate tectonics, to the core of ancient North America, “Laurentia”. The time slice maps are taken at 5-10 million year intervals over the past 550 million years. (PerryGeo has created a fantastic animated gif of these maps!)

The projects website contains 40 of the most representative time slices. From these maps you can witness how the physiography of Laurentia has changed through geologic history. Mountains rise, rifts open, deserts form, and lakes deepen as the earth’s tectonic plates subside and become reborn.

Of particular interest to me is the time slice of Late Triassic (210Ma).

Eastern Pennsylvania sits contently just above the Triassic equator. Africa has recently slammed into the East Coast forming the super continent of Pangaea. This collision, the Appalachian orogeny, is reminiscent of the modern collision of India and Asia. The mountains formed on the East Coast may have been as grand as the Himalayas. But by 250 Ma, Africa and Laurentia have been sent on their way. A rift basin develops as the two continents drift in opposing directions.

Along the Eastern Seaboard of the US, this Triassic basin (geologic history) widened and deepened as huge blocks of the earth dropped due to tensional stress. Lakes formed within many of these half graben basins. Some of these lakes would rival the Great Lakes and Caspian Sea.

In Eastern Pennsylvania, erosion from the massive mountains to the West was transported in to this basin. Large chunks of rock and sandy sediment were moved by water and gravity to form mud chocked braided streams and gravely sand bars on the margin of the newly formed lake. As the basin deepens, the lake goes through cycles of drainage and enclosure. These cycles change the depth and depositional regime of the basin lake. Some times shallow, the lake deposits are sandy and exposed to air and the critters that roam the area. At other times, and in other areas of the lake, it is incredibly deep and deprived of oxygen. Thin chemical laminea are deposited in these areas. As the mountains eroded and the subsiding resigned the basin in-filled and shallowed again. In the hot and dry region above the equator, the deposits on the lake margin formed a playa like environment. The muddy shoreline cracked and split as it was wetted and then baked by the sun.

For the next few million years, the lake shallowed and the mountains eroded. As pressure was release, the Earth thrust magma into near surface chambers and lava outflows. Into the Cretaceous and Tertiary periods of the past 150 million years, the regal mountains which once supplied the Triassic lake with sediment are eroded to reflections of their former selves. The sediments of the Piedmont and Coastal Plain are now the home of the highest peaks.

Since I am no geologist, understand that this description may be a bit fictitious, but it is the way I like to see it.

Head on over to the CAA blog to read some more, or to read another rendition of the geologic history of Laurentia, based on these maps, check out the BLDGBLOG.

(Pictures are credited to Dr. Ron Blakey. Fantastic work!)

From a story recently covered at the Science Blog. Researchers from NASA and the University of New Hampshire in Durham have discovered a number of previously unknown Mayan temple ruins in a densely forested region around San Bartolo, Guatemala. The team employed the use of NASA’s Airborne Synthetic Aperture Radar (AIRSAR) to remotely sense the jungle floor. Flown from 8km above the relative topography, AIRSAR’s long wavelength allows it to penetrate the jungle canopy and collect data that has escaped other methods.

The research team noticed a “fingerprint” in vegetation growth patterns that indicated the possible presence of a Mayan ruin. On field checking, it was quickly learned that the fingerprint is the result of differential moisture and vegetation growth due to the limestone building materials used by the Mayans.

The remote sensing segment of this project is combined with a detailed climactic study which leads the researchers to conclude that the Mayan civilization may have crumbled due to a series of disruptive climactic events. A better understanding of these cataclysmic processes and their impact on societies will help inform modern nations on how to avoid such pitfalls.

The AIRSAR system was developed in 1988 by the Jet Propulsion laboratory at the California Institute of Technology. The AIRSAR missions covering South America were flown in March 2004. Other archaeological applications of the AIRSAR technology include extensive work at Angkor, Cambodia [also, a great PDF], temples in Nakhorn Ratchasima province, Thailand, 19th century plantations in Georgia, and a study in Tikal, Guatemala to be presented at this years Computer Applications and Quantitative Methods in Archaeology Conference.

With location specific information and services becoming widely available, the privacy and restriction of these data becomes very important. GeoPriv is a transfer protocol (in development) aimed at authorizing the delivery of and rendering location specific information.

The basics of this protocol, as I understand it, is an authorization system built from a rule set (policy) which is composed of Conditions, Actions, and Transformations. This policy is stored as an XML document or in a relational database on the location server. The Condition segment of this policy is a set of expressions that are based on certain variables, such as requester identification, server information, and external variables derived from the location itself. These expressions are interpreted as TRUE or FALSE and the Action of PERMIT is granted if the conditions are met. Lastly, the Transformation is an algorithm with defines the resolution at which locational information will be delivered. The transformation combines the union of the permissions to define the requesters level of accuracy. These transformations, as well as the entire policy is intended to be extensible for specific application use.

It appears that the implementation of this protocol could be useful in displaying location sensitive archaeological sites. As I mentioned in a previous post, archaeological site location is highly guarded by both the state government and the archaeologists who investigate them. The fear of looting and disturbance is often cited as the reason for such secrecy. Although, I understand these concerns, I also feel that in a time when archaeologists justify our existence with the preservation of “the Publics’” heritage, we need to loosen our death grip on where sites are so the publics can feel the same senses of place that we do. All rants aside, the GeoPriv protocol, with the use of locational transformations could be a useful tool in disseminating resolution adjusted information on site locations based on conditional rules.

I admit, I only have a general understanding of the specifics of this protocol, so please investigate it a bit (they also have a list-serv) and let me know what you think.

Sorry for the delay in posting. I have been in the field recently working on two very cool projects that include lasers, prisoners, robots, and yes, 18th century grist mills. I will write up each of these projects when they stop making me shovel for my paycheck.

Launched Thursday night, Google Local is now including map icons to draw attention to a small set of advertiser in the new Local Business Ads program. The advertisers icons, once clicked, display sponsored link information including address, phone number, and a jpg logo.

A Search for “Ralph Lauren NY” turns up an example of this new ad technique (is that the ICQ chat icon?). According to an article at CNET, the ad icons will not be included in Google Maps accessing the API.

As blogged at SlashGeo, check out the top ten list of WMS (Web Mapping Services) layers over at the PerryGEO blog.
The 10 WMS layers compiled my Matt Perry are a set of key base layers that can be pulled together in a web mapping interface such as MapServer, BeeldBlab, OpenJUMP, ArcIMS.

Also, Matt’s blog post includes tips on displaying data availability and a slick MapServer app with the included mapfile.

Check out the rest of PerryGEO for some great nuts and bolts GIS, including a way to script a KML to Shapefile converter!

As reported on Digg.com (and subsequently Dugg all to heck), here is a very cool GPS + Camera combo project. Simple concept; take a camera that supports recording GPS coordinatess in the image Exif data(Exchangeable Image File = like metadata for pictures), hook it up to a GPS, write a script to process the results into XML, put it on a google map. Check out the examples at the creators site.

Although, the idea of a GPS enabled camera has been floating around for a while, this is the first time I have seen productive results in a method that is easily reproducible (thanks to IceBurn’s sharing of his Exif data to XML Perl script). Such a technology would be a boom for many types of field survey. Particularly, this tool would be incredibly useful in Historic Resource survey. Unless you are using handheld field data loggers, you are probably heads-up digitizing your locational info from a paper map or even Geocoding addresses. Then, photos needs to be renamed from photologs and plugged into your GIS by any number of ways. With the locationally aware camera, metadata could be associated with each photo via the ability to include Exif data or the GPS units data logger. With a script similar to IceBurn’s Perl script, your location and photographic data is one step away from production. I can already hear the client’s giddy laughter as the click a link and up come a Google Map with the days survey results published within a half hour of completion.

Stop by IceBurn’s liar to check out his Geo-Camera and the great examples he has posted.

Edit: After doing a little searching I found the Richo Pro G3 GPS Camera. Including CF WAAS GPS, Bluetooth, and ESRI ArcGIS software to take care of all the dirty work. Very cool!