【每日阅读训练第四期——速度越障4系列】【4-09】科技-space archaeology

babybearmm

[warm-up]
TALKS     | IN LESS THAN 6 MINUTES

Sarah Parcak: Archeology from space
http://www.ted.com/talks/lang/en/sarah_parcak_archeology_from_space.html




Time Traveling Via Satellite

[计时一]

MICHAEL PALACE majored in archaeology and environmental science at the University of Virginia, then turned to the environmental science side of things as he pursued his master’s degree at UVA. For his thesis he studied the dynamics of Costa Rican howler monkeys in relation to landscape-level vegetation structure. The monkeys would move about with the shifting wet/dry seasons and Palace would gather data by tagging along like an outlying member of the troop. On the side, he would often train a microphone on the howlers’ loud morning choruses, which he would later use in his semi-professional career creating electronic music blended with audio field recordings.

Despite the inherent difficulties imposed by research in remote reaches of tropical rainforest, the jungles of Central America got into Palace’s blood. Next stop on his academic ascension was UNH where he linked up with Michael Keller, project scientist for the NASA-sponsored, Brazilian-led Large Scale Biosphere Atmosphere in Amazonia (LBA) project. Palace relished the opportunity to explore the tropical rainforests of South America and, while pursuing his Ph.D., worked full-time with Keller conducting research in three regions of the Brazilian Amazon. Among other things, he wrote computer programs and databases to visualize and statistically analyze trace gas measurements.

Abstruse scientific stuff. But Palace, now a tropical ecologist and research assistant professor at the Complex Systems Research Center (CSRC) within the Institute for the Study or Earth, Oceans, and Space, has come full circle with a $364,063 grant from NASA’s Space Archaeology Program. For the three-year project he won’t be using satellite remote sensing technology to estimate things like tree canopy dynamics or overall forest biomass. Rather, he’ll use the high-tech methods to help nail down much-disputed population estimates of pre-Columbian indigenous peoples in the Amazon Basin lowlands. The project will integrate his knowledge of remote sensing, tropical vegetation, and his interest in archaeology.

[308 words]

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Collaborating with a Brazilian archaeologist and another ecologist on the project, Palace will use imagery from an instrument onboard NASA’s Terra satellite to locate “Amazonian black earths” or, in Portuguese, “terra preta” sites that designate areas where indigenous Amazonian peoples lived and worked the land prior to colonial contact back in the late 15th century.

“This is a big issue because people think there may be thousands of terra preta sites across the Amazonian basin,” Palace says adding, “and if we can show they are indeed that extensive it will really change our understanding of how many people lived in the region and the impact they had on what we still perceive to be ‘pristine’ forest.”

Currently, pre-Columbian population estimates vary widely - from 500,000 to 10 million - and are the subject of much controversy and debate. Knowing with more accuracy how many people might have impacted the rainforest through agriculture and development prior to European contact will help scientists understand how the Amazon Basin might withstand current pressures from deforestation, selective logging, and development.

Palace still views himself as a tropical ecologist working at the landscape level, but to study the immense Amazonian forest he has become an expert in using satellite-borne imagery. In this project he will use hyperspectral imagery taken by NASA's Hyperion sensor.

[218 words]

[计时三]

The Hyperion camera "sees" in 220 spectral bands of light, allowing scientists to identify the chemical makeup of tree leaves, which in turn is related to nutrients in the underlying soil. The more nutrient-rich leaves or specific groups of tree species seen by Hyperion will be the signature for the Amazonian black earths Palace is looking for – sites containing soil rich in organic matter, charcoal, and nutrients and frequently associated with large accumulations of potsherds, bone, and other artifacts of human origin. The soils were created hundreds of years ago when indigenous populations slowly burned trees to make soil equivalent to "biochar," which is extremely efficient at storing carbon and nutrients and provides fertile, productive farmland.

"There are terra preta sites all over the Amazonian basin, particularly near rivers and bluffs, but no one really knows their whole distribution," says Palace, who will collaborate with Mark Bush, an ecologist from the Florida Institute of Technology, and Brazilian archaeologist Eduardo Neves of the University of San Paulo. Also collaborating on the project are Stephen Hagen, a research scientist at Applied GeoSolutions in Newmarket, N.H. who received his Ph.D. at UNH, and former CSRC faculty member Rob Braswell, now at Atmospheric Environmental Research, Inc. in Lexington, Mass.

[205 words]

[计时四]

Having identified terra preta sites in the Hyperion imagery, the researchers will, among other methods, use a “neural network” – an adaptive mathematical system that will learn to identify the difference between sites that are terra preta and those that are not using the complex data from the Hyperion imagery. Says Palace, “Once we develop the neural network model we’ll be able to extrapolate across the entire Amazon landscape and identify the location of other sites. This will allow archaeologists to go there and determine if they are indeed terra preta and, from that, we should be able to accurately estimate the indigenous population prior to colonial contact. We will also be able to look at the connectivity and spatial dimension of these sites across the landscape and compare the location with other geological and geographic information."

At six million square kilometers, the Amazon basin contains the largest continuous rainforest in the world and constitutes 40 percent of what remains of this ecotype. If Palace's research indicates there was a large population of indigenous peoples using the forest to maintain a highly productive agricultural system, it is likely that Amazonian forest vegetation was significantly altered and may be thought of as a cultural artifact, resilient to human disturbance and not an undisturbed forest.

“The indigenous peoples probably had some sort of cycling system where they would burn fields and forests, let them grow back to a certain extent, and let mixed crops and certain types of trees grow,” Palace says. He adds that his Brazilian colleague, Eduardo Neves, has determined that three types of palm trees are prevalent in terra preta sites. “So in addition to the nutrient signature in the hyperspectral signal, we might also be seeing specific species of trees that will help us locate these areas.”

[298 words]

[计时五]

Palace will travel to Brazil to confer with his colleagues but the Amazon project will not involve any fieldwork on his part. However, a simultaneous project recently funded by the NASA New Investigator Program in Earth Science will take him back to Costa Rica where he will examine tropical forest structure using multiple remote sensing platforms, including airborne lidar.

“Lidar is a type of laser that, with the right application, can give you the shape of the whole forest from the ground to the top of the tree canopy,” Palace explains. “I’m creating a method of using lidar to understand both the forest understory and the tree canopy, which will help determine the forest structure in three dimensions.”

The same techniques used in Costa Rica can also be applied other types of habitats, including New England landscapes. Palace is doing just that as principal science investigator on a project examining Lyme disease in New Hampshire, which is funded by NASA's Experimental Program to Stimulate Competitive Research (EPSCoR) program.

The remotely sensed data includes highly detailed biophysical and biochemical information derived from satellite-based optical and radar imagery of the landscape favored by white-tailed deer and small rodents – important hosts for the tick species responsible for transmitting Lyme disease.

Back in Costa Rica, Palace will also continue work in his nonscientific endeavor of making field recordings that he uses to create “generative” electronic music under the pseudonym. “horchata.” Described as “a crafter of sonic landscapes” by one reviewer, horchata has recorded a number of albums and wrote the soundtrack to the documentary film about global warming titled "Out of Balance: ExxonMobil's Impact on Climate Change."
[273 words]

http://archaeologyexcavations.blogspot.com/2010/08/time-traveling-via-satellite.html


[越障]

NATURE | NEWS
Satellites expose 8,000 years of civilization


Archaeologists develop large-scale method to identify ancient human settlements.


Virginia Gewin
19 March 2012

[attachimg]103060[/attachimg]

Hidden in the landscape of the fertile crescent of the Middle East, scientists say, lurk overlooked networks of small settlements that hold vital clues to ancient civilizations.

Beyond the impressive mounds of earth, known as tells in Arabic, that mark lost cities, researchers have found a way to give archaeologists a broader perspective of the ancient landscape. By combining spy-satellite photos obtained in the 1960s with modern multispectral images and digital maps of Earth's surface, the researchers have created a new method for mapping large-scale patterns of human settlement. The approach, used to map some 14,000 settlement sites spanning eight millennia in 23,000 square kilometres of northeastern Syria, is published today in the Proceedings of the National Academy of Sciences.

“Traditional archaeology goes straight to the biggest features — the palaces or cities — but we tend to ignore the settlements at the other end of the social spectrum,” says Jason Ur, an archaeologist at Harvard University in Cambridge, Massachusetts, who is co-author of the study. “The people who migrated to cities came from somewhere; we have to put these people back on the map.”

Such comprehensive maps promise to uncover long-term trends in urban activity. “This kind of innovative large-scale application is what remote sensing has been promising archaeology for some years now; it will certainly help us to focus our attention on the big picture,” says Graham Philip, an archaeologist at Durham University, UK.


Soil signatures

The satellite-based method relies on the fact that human activity leaves a distinctive signature on the soil, called anthrosols. Formed from organic waste and decayed mud-brick architecture, anthrosols are imbued with higher levels of organic matter and have a finer texture and lighter appearance than undisturbed soil — resulting in reflective properties that can be seen by satellites.

To sift through satellite images for those signatures, co-author Bjoern Menze, a research affiliate in computer science at the Massachusetts Institute of Technology in Cambridge, built on his skills from his day job identifying tumours in clinical images.


Menze trained software to detect the characteristic wavelengths of known anthrosols in images spanning 50 years of seasonal differences. This automation was key. “You could do this with the naked eye using Google Earth to look for sites, but this method takes the subjectivity out of it by defining spectral characteristics that bounce off of archaeological sites,” says Ur.
 
Menze and Ur also used digital elevation data collected in 2000 by the space shuttle as part of NASA's Shuttle Radar Topography Mission (SRTM). This information enabled the authors to estimate the volume of the larger sites for the first time — and to use this volume as a proxy for a site’s longevity. The bigger the mound, the longer the settlement survived.


Tony Wilkinson, an archaeologist at Durham University and Ur’s former mentor, says that being able to measure the volume of many sites over large areas remotely is a breakthrough. However, Philip cautions that the resolution of the SRTM data may be too coarse to provide an accurate measurement for the volume of the smaller settlements. Nonetheless, he expects that the method will spark new archaeological insights for several different regions.

New life for old hypotheses

The method has already renewed speculation about the importance of water to city development. Surprisingly, this study found that a handful of sites are unexpectedly large given that they are not located near rivers or in areas of high precipitation. “The settlement known as Tell Brak, for example, is far too large for what one would expect at such a marginal position,” says Ur. “This is where things get interesting.”

Jennifer Pournelle, a landscape archaeologist at the University of South Carolina in Columbia, agrees. “These findings validate hypotheses I’ve introduced in southern Iraq — namely that irrigation is an after-effect of urbanization,” she says. “It’s not what enables a city to develop; it’s what keeps them going after soil moisture dries up.”

Pournelle says that she plans to adopt this method as soon as possible, and notes that it offers a valuable way to learn more about large regions, particularly when they are remote and difficult to access because of local conflicts.

[712 words]

Nature doi:10.1038/nature.2012.10257
http://www.nature.com/news/satellites-expose-8-000-years-of-civilization-1.10257?WT.ec_id=NEWS-20120320

ladyMcc

2'25''

Palace has experiences in different fields.

1'33''
Palace will use imagery taken by satellite to estimate the population and impact in Amazon,

estimating how much pressure Amazon can stand .

1'22''

The imagery taken by satellite help scientist to identify the components conducted to the

leaves,in this case,Palace can make a estimation on which site once is a habitat for

ancient people.

2'04''

Further more ,They use another mathematic way to find the difference between site and determine

the population live on the sites.besides,they add a new method depending on special species to

determine the site location.

1'51''

airborne lidar will be used in Palace's further study,a method can provide the shape of a forest from

the understory to the canopy of trees. Back to CR he will continue his work on generative music.

4'39''

Introduce a method based on multispectral images and the difference between old technologies and

the new method.

Elevation data.........the bigger earth mound,the longer the site survived

Different opinion concerning relationship between irrigation and urbanization

bblruuu

板凳是我

铁板神猴

I get the floor. Today's topic is sooooo cool!!

luruisha

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暮已央

来晚了~占位
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hexiaomu77

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  The new method using the combination of satelites and digital photos to detect the long settlements of human being.
1、 Introduce this method: remote sensing way to detect the pattern of soil, the lighter and finer, the more likely to be the settlement of people; we can also trace the different seasonal change during the ancient period through  the Globle earth observing with naked eyes;more bigger the mount, the more longer the settlement last.(also mention a drawback of this method)
2、An additional deductive may: water, the precipitation, or irrgation

corneliaflower

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icyseason

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越障：4′26 Introduce a new method that combine satelites and digital photos to detect the long settlements of human being.
                 A detailed introduction;bigger the mount, the more longer the settlement last

romanyck

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