Ground-penetrating radar is the technology behind the discoveries of what are believed to be unmarked burial sites on the grounds of former residential schools, by providing communities with the first glimpses of physical evidence of possible graves.
toronto.citynews.ca
''Ground-penetrating radar is the technology behind the discoveries of what are believed to be unmarked burial sites on the grounds of former residential schools, by providing communities with the first glimpses of physical evidence of possible graves.''
The basic principle, Supernant says, is that ground-penetrating radar sends an electromagnetic wave into the ground. As the wave travels below the surface it encounters different things and bounces back to the machine.
She says the unit itself looks like a box, roughly the size of a toaster oven, which is usually attached to a cart that someone pushes along the ground.
When her team does searches, they divide the area into a grid and walk a line with their ground-penetrating radar unit. It can be a slow process, Supernant says, depending on the size of the area being searched.
“When we’re using it to try to locate potential unmarked graves, what we’re really doing is we’re sending that signal through the ground and then trying to create a map of what we think we see below the surface.”
She says people should think of the soil as a background signal.
“That’s why you hear terms like ‘anomaly’ used, because there’s sort of a steady background signal and then something changes and we try to make sense of (what) that change might represent.”
Could mud be the key to solving the country’s coldest murder cases? One forensic soil scientist certainly thinks so…
www.readersdigest.co.uk
''Over the last five years there have been significant advances in soil analysis, enabling fingerprint information to be obtained from a sample the size of a grain of rice. Not so long ago they’d have required a shovelful for the same results.''
''Lorna has to keep an open mind about the suspect, who could be perfectly innocent, as well as any events which may have altered the chemical composition of the soil, such as a tool having been washed, or shoes splashed through a puddle. Interestingly, adding water to soil can sometimes help investigators because when it dries, tiny sticky aggregates can be locked-in''
Forensic Soil Analysis is the use of soil sciences and other disciplines to aid in criminal investigation. Soils are like fingerprints because every type of soil that exists has unique properties that act as identification markers. This means that the origin of the soil sample can be identified...
www.crimemuseum.org
''Forensic Soil Analysis is the use of soil sciences and other disciplines to aid in criminal investigation. Soils are like fingerprints because every type of soil that exists has unique properties that act as identification markers. This means that the origin of the soil sample can be identified. For example, clay embedded in the sneaker of a criminal can be traced back to a specific clay type found along a lake where a murder victim was discovered. The majority of soil cases involves footprints or tire marks that have been left in the soil.
The unique properties of soil are as follows:
Sediment– the original solid particles that were weathered and transported. This could be in the form of a grain of rock that breaks off of the larger parent material (larger version of rock). Soils can develop on these sediments due to physical and chemical alteration.''
www.independent.co.uk
