There are over 110 million landmines in at least 68 countries worldwide still present today. There are many military and humanitarian efforts underway to detect and remove them.
Detection
The first step in the removal of landmines is to detect them. There are several methods used today and one of the methods dates back to WWI. Dogs have been used for many years to sniff out TNT and detect mines, although a relatively new program in Africa is using giant rats, which are called HeroRats, and is gaining popularity. Metal detectors have been used for many years, but tend to be unreliable in the sense that they miss minimum metal mines or give false positives. A method dating from WWI is the mine roller method where the armored vehicle rolls over the mine field and will hopefully detonate it. It is not reliable and generally needs another method to recheck the field for missed mines. There is also the mine plow, where the plow is put on the front of a tank to turn over the soil and expose the mines, or at the very least, turn them over to reduce the impact if they do detonate. Armies are now using remote control vehicles and helicopters to reduce the risk to humans. Helicopters have dangers associated with them because the plow that they drag can snag on a large rock or boulder and bring the helicopter down. They have come up with pressure sensitive plow rakes but if the mine is planted in a rocky terrain or hard ground, the helicopter can not drag for them.
Disarment
Once the mines have been detected, there are many options available to make the mine field safe and disarm the mines. Manual disarmament is one option where the technician puts on protective gear and attempts to take the mine apart and disarm it. Another method is the remote burning of the mine, in which case if done properly, it will not detonate the mine. Diethylene triamine will generate heat once it reacts with the TNT and cause it to combust without exploding. They can also put a hole in the mine and set it on fire without detonating the contents.
Detonation
If it is too risky or time consuming to try and disarm the landmines, there are other practices in use to detonate them. One option is the Bangalor Torpedo. It will carry an explosive-filled pipe across a field to clear a path.
Some inhumane methods include letting cattle and other heavy livestock graze the mine fields to detonate the mines and, previously, the Nazi Germans would release their captives and chase them across mine fields for the same result.
Developing Methods
There are several new methods being tested to detect mines. Ground penetrating radar is a method that is still as yet, unreliable. It can pick up non-metal explosives but the problem lies in that it also picks up rocks, tree roots and other solids in the soil. Surprisingly, honey bees are being trained to detect mines. The University of Montana has learned that they detect mines with far greater accuracy than dogs or rats. A dual-sensor using GPR and metal detector sensors is being developed by several companies.
A plant, the Mustard Arabidopsis Thaliana, is being developed to detect for mines. Scientists have developed a strain that will change colors when it comes in contact with the nitrous oxide that is emitted by landmines. It is not 100% reliable yet and scientists are working to make the plant less sensitive to organic emissions of nitrous oxide.
Nuclear reactions are being developed to detect landmines. This method utilizes neutrons in detection by watching for gamma rays that are emitted from the nitrogen that is contained in the landmines.
The last method being developed is the accoustic detection method. This method uses sound waves to make the land mine vibrate and thus is detectable.
This article is written by Jet Russell. Jet does outreach for a landmine clearance orginizatin and loves to contribute to the blogosphere in his spare time.