CHARLES WERNER
Firehouse.com TechZone Editor
ROBOTS AT THE WTC
Robots played a critical role in many ways at the WTC. The Center for Robot-Assisted Search and Rescue responded with its diverse cache of robots within 6 hours to the WTC disaster with teams from Foster-Miller led by Arnis Mangolds, iRobot led by Tom Frost, SPAWAR (Navy) led by Bart Everett, and the University of South Florida led by Robin Murphy. Center personnel remained on-site through Oct. 2.
The first two weeks focused on searching the rubble pile and neighboring buildings, while the second two weeks concentrated on inspection of the basement and slurry wall structure. As noted in the New York Times, "...about a dozen remote-controlled machines were employed at the disaster site. Ranging from the size of a shoebox to that of a medium-size suitcase, they crawl in, under and around the twisted steel and crushed concrete, guided by human operators on the surface. Using lights, video cameras and sensors, they search for victims in places where human rescuers cannot or dare not go.
Photos Courtesy The Center for Robot-Assisted Search and Rescue
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Most of the robots are experimental prototypes financed by sources like the National Science Foundation and the Office of Naval Research. While some were built from scratch, others are customized versions of commercially available robots. They were designed originally for tasks as varied as military reconnaissance, defusing explosives and safety tests at nuclear and chemical installations. Some were brought out of retirement after the Sept. 11 attacks."
Future rescue missions may see more of this type of technology. Natural disasters, explosions, radiation accidents, or other chemical or biological incidents could well be the standard setting for such equipment.
Photos Courtesy The Center for Robot-Assisted Search and Rescue
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These robot units are very versatile as they can manipulate their size and get into areas that are very confined and otherwise inaccessible by humans. They can be equipped with video cameras with infrared capability with the images sent to rescue working on the surface via a cable or wirelessly. In a safe way, rescuers can determine the dangers and the necessity of further exploration.
SEISMOLOGICAL INFORMATION RECORDED AND ANALYZED
Similar to the Oklahoma bombing, seismological devices recorded the explosions and the collapse of the WTC. In this article, you will find links that will provide visual reference and related data about seismological information during the WTC attacks.
Magnified waveforms of the WTC attacks can be found Here.
A REPORT: SEISMOLOGICAL OBSERVATION OF IMPACTS AND COLLAPSES AT WORLD TRADE CENTER
Prepared by: Seismology Group
Lamont-Doherty Earth Observatory, Columbia University
Palisades NY 10964
Seismograph stations in southern New York, northern New Jersey, western Connecticut, and Pennsylvania, operated by the Lamont-Doherty Earth Observatory of Columbia University, recorded the collapse of each of the towers of the World Trade Center on Tuesday morning September 11 and the subsequent collapse of 7 World Trade Center later that afternoon. The closest station, at Palisades, New York, is located 21 miles (34 km) north of lower Manhattan in Rockland County. This station also registered the impacts of the two airliners that crashed into the towers. The signals generated by the collapsing North and South towers were much larger than those from the two airliner impacts. The signals generated by the collapse of Building 7, however, were smaller than those of the impacts. In addition, many smaller signals were registered at Palisades throughout the rest of the day that may have originated from the further collapse of the Twin Towers and the fall of walls and other debris in the surrounding area.
The Palisades recordings of the Twin Tower collapses were comparable in size to the signals from a small earthquake of seismic magnitude 2.4 that was felt in the east side of Manhattan and in the western parts of Queens earlier this year, on January 17. The seismic signals from the five events on 11 September differed from a small earthquake in that they were richer in low-frequency energy and poorer in high-frequency energy. These differences can be attributed to the short time duration of the fault rupture responsible for the earthquake as compared to the long and complex collapse of the buildings. The seismic waves from the five World Trade Center events resemble those produced by the collapse of a salt mine south of Rochester, in 1994. The catastrophic events at the World Trade Center, as might be expected, produced much larger seismic effects than the bombing of the World Trade Center in 1993. The seismic effects of the collapses are comparable to the explosions at a gasoline tank farm near Newark on January 7, 1983, which were detected up to 130 miles away.
The seismographic stations are part of the Lamont-Doherty Cooperative Seismographic Network, which is operated in conjunction with several other institutions and is supported by the U.S. Geological Survey under the National Earthquake Hazard Reduction Program. As part of its agreement with the USGS, Lamont-Doherty makes this data available upon request without restriction.
Preliminary measurements made by Lamont-Doherty analysts are summarized in the Table below: Information Based on Seismic Waves recorded at Palisades New York
Event
Duration
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origin time (EDT)
(hours:minutes:seconds)
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Magnitude
(equivalent seismic)
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Impact 1 at North Tower
12 seconds
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08:46:26±1
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0.9
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Impact 2 at South Tower
6 seconds
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09:02:54±2
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0.7
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Collapse 1, South Tower
10 seconds
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09:59:04±1
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2.1
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Collapse 2, North Tower
8 seconds
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10:28:31±1
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2.3
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Collapse 3, Building 7
18 seconds
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17:20:33±1
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0.6
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NASA and Technical Assistance (Information provided by NASA) NASA has the ability to see views of ground zero in New York City that human eyes can't detect, so now the space agency is helping with the recovery efforts. This resource proved invaluable. NASA answered technical questions that FEMA's staff did not have the capability to address. It was not difficult to acquire images from both space and the air, but disaster managers from New York and the Federal Emergency Management Agency (news - web sites) had a hard time putting the high-altitude views to use.
NASA's environmental satellites have been looking down at the world, providing eye-opening vistas since the early 70s. Using this expertise, NASA's specialists helped provide important early answers during the aftermath of the attack on the World Trade Centers. One way they helped was to process the images to remove the smoke. This helped rescuers find their way to ground zero.
Another important clue from the high-altitude images was where voids could be found in the ruins -- places where survivors could have been clinging to life and waiting desperately for rescue. NASA also flew a high-altitude scanner over the carnage. "Which made the initial pass and was able to indicate the lack of asbestos, in any measurable form, on the ground," Davis said.
That one single finding has made it easier to put more people to work more quickly at ground zero -- avoiding asbestos countermeasures that would have made the whole effort even more costly.
IDENTIFICATION AND THE USE OF DNA (Information from Forensic DNA Consulting)
One big problem from the WTC attacks was a huge number of unidentified bodies and body parts. Many were probably incinerated in the explosions; others are still buried in the rubble. But over the next few months, the New York City Medical Examiner's office will be faced with the momentous task of trying to determine the identities of the thousands of recovered victims and of reconciling body parts.
For those bodies that are relatively intact, physical features, paper identification, or various accoutrements will be used. These are the most expedient and least expensive ways of identifying a body. For those bodies where it is possible, forensic odontologists will try to match dental records to the dentition of victims. Teeth are the strongest material in the human body, and often survive when nothing else does. However, for bodies or body parts where the dentition is missing or fragmented, and they cannot be otherwise identified, DNA typing will be used to identify them.
To identify physiological material using DNA, a reference sample is needed. These days, this can be as small as the cells left on a toothbrush or the roots from hairs left in a hairbrush. Families will be asked to collect these and other similar items and submit them to the NYCME DNA Laboratory to form a reference database. Special software is being made available by the FBI for the purpose of linking DNA profiles obtained from evidence samples with those in the reference sample database.
If no convenient reference sample can be obtained for a missing person, relatives may be asked to donate samples. These samples can be used in two ways. Scientists can use the laws of genetic inheritance to determine whether a profile from an unknown victim could be the child of two particular parents. This is not conclusive, for other possibilities exist, but within a closed reference pool, some victims may be identified by default.
DNA collection information for WTC victims available from the NYC website.
