Electroreception which is a form of captor of energy activating a sense or pulse in some sharks species; it will be active in water in a ratio of ~ 3.6749 by gm/s so, 454 g will be perceived at 1668.40 m and 5000 x 454g at around 834115 m or 834 km upon or calculus and formula. Probably sharks use depth of water and Earth rotation to close in. Their « ampullae de Lorenzini » have already identified or similarly detected a type of prey by triggering something recorded in their brain; a type of fish or prey by association to the weight, velocity, water displacement or sound, sonar like whales could communicate; they just have to close in. A prey that is wounded might leak salt in the water to a very low level, they would then detect a leak, just as air leaks could be detected.
Sharks can sense the tiniest changes in this electrical current, down to one-billionth of a volt [source: Fields]. If two AA batteries were connected 1,000 miles (1,600 kilometers) apart, a shark could detect if one ran out [source: Viegas]
The invention of infrared thermal imaging by Astronomer William Herschel in 1800, which was initially used for military purposes is mostly what could resemble to Pistris (Sharks, in latin) detection system, however water pressure plays a role in this process. As molecules of water in concentration pile on each other it squeezes a thinner path for electric current to spread or evade, Infra Red or blue wavelength is also perceived from certain species vs other, it is the current that matters. Being lighter it goes upwards to the surface from different concentrated lattices of H2O like bubbles of air are heading to the surface in a sense. Electroreception could be perceived at 3 meters as mentioned in some sources but we believe 3 meters of radius. So the shark would be at a closer distance as their maximum depth would be at 12 000 feet. But the reach in water could be that maximum distance according to the weight or the concentration of water troubled including wavelength changes.
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