Three questions on the simultaneous explosion case investigation of the Boston marathon

It was held at Boston, Massachusetts, USA around 15:00 local time at 2:45 pm (3:45 am Japan time)"Boston marathon"Two explosions occurred near the goal of the state investigation authorities, three people including an 8-year-old boy died, more than 141 injured people received allowance, 17 of them were serious It seems. The Boston investigation authorities and the FBI are still under investigation at the work site, but what kind of investigation is being done on the ground in the first place? Three questions on the site investigation of the explosion incident to the American web magazine "SlateIt answers.

Boston Marathon bombs: How strong were the bombs? - Slate Magazine
http://www.slate.com/articles/news_and_politics/explainer/2013/04/boston_marathon_bombs_how_strong_were_the_bombs.html

At the moment, the details of the moment of the explosion incident which is seen as "the possibility of terrorism is high" can be confirmed in the following article.

There are two explosions at the Boston marathon goal point, three people died, more than 120 people injured


◆ 01: How do bomb survey teams examine the power of the explosives used?


In the case of the explosion this time, the first explosion damaged the four window glasses near the goal by the shock at the time of the explosion. According to Slate, it seems to be possible to identify the power of explosives used by examining damaged walls, windowpanes, cars, and victims in the event of an explosion. For example, in a place where the surroundings were opened, 7 kgTNTExploded, the wall of the brick about 13.7 meters away from the hypocenter was cracked, the wall made of gypsum 35 meters away andAsbestos boardDamaged, 64 meters awaySingle windowIt is said that it will be crushed. Also, the eardrum of a person standing within 12.2 meters from the hypocenter will be damaged, and those within 3.7 meters may die. However, the verification results obtained from these pieces of information are fairly rough.

ByHahatango

To obtain more accurate findings, the bomb survey team,Ion mobility spectrometric explosive detectorWe will investigate using. This explosive detector is a drill-like shape without a cord that detects chemicals that have taken in air and have not yet exploded. If the detector detects an explosive substance even if it is 1 nanogram, the red light is lit. The technology being used is the same as the machine which performs the security check at the airport, but it is more portable. However, since explosives are not particularly volatile and do not remain in the atmosphere for a long time, the ion mobility spectrometry explosive detector has a declining detection capability as the time elapses since the explosion There is also a weak point that it goes.

ByHigh pit wilma

◆ 02: What information can be obtained from the white smoke filled in the field right after the explosion?


To put it straightforwardly, the color of smoke is the criterion for determining the fuel of the explosive and how much heat it is taking. For example, a fire burning at a high temperature may cause more fuelCarbon absorbing light with extremely small particles, And this carbon appears as black smoke in the air.

ByBill Liao

Low temperature burning produces incompletely shaped carbon that reflects in the air rather than absorbing it, so it appears to be white smoke in the atmosphere.


The substance generated when the fire is burning is basically carbon dioxide and moisture, carbon dioxide can not be seen in the air, but moisture in the atmosphere brightens the color of the smoke generated during combustion can do. For example, in the case of a forest fire, the water vapor generated by burning wood containing much moisture may mix with black smoke generated by the burning of other substances and turn into a gray fire cumulus cloud.

ByErik.Nielsen.Photos

Oil will tend to produce black smoke as most fuels are converted to carbon when burning and plastic products containing petroleum products also burn while generating dark colored smoke.

ByPaul L McCord Jr

◆ 03: How do explosive detection dogs become able to separate the smell of explosives?

ByOnceAndFutureLaura

Explosive Detection Dog training uses classical conditional training that gives rewards for food and toys. Also, dogs that are suitable for explosive detection dogs do not aggression even under high tension conditionsLabrador RetrieverAnd that.

ByJfch

Detecting explosives A dog to become a dog receives special training for 10 weeks and touches 120 gallons of explosives a day at a minimum of 1 gram and a maximum of 1000 pounds (about 454 kilograms) during that period.

ByParanagus

Dogs are ordered to sit every time they detect the smell of an explosive in the early stages of training, and learning that sitting is a signal of bomb discovery. Also, you can give food for reward only when you are detecting bombs. To give food without complimenting or playing as a reward is to make it possible to act without interruption not only with a specific person but also by other people. If a certain trainer gives a reward to the dog under training or playing it, a stronger bond with that person is created, and when the dog behaves in collaboration with other people, the original ability It seems that it can not be demonstrated.

ByHarezou

In one stage of training, training will be conducted to find explosives from a total of four containers - explosives, foods, containers with explosives with different smells than bombs, and empty containers. Explosive Detection Dogs are required to be able to identify thousands of components that can be used for explosives. Dogs under training will be trained to use substances found from various types of bombs and will be able to identify explosives by remembering the smell of the substance.

ByPort of San Diego