What will happen when lightning strikes on the surface of the deep sea?

Question

The lightning is having enormous amount of energy, as it strikes the ground it makes various electrical and magnetic effects. If the lightning strikes a tree, that will be burst by lightning.

1. Suppose if the lightning strikes on the surface of the sea, what will happen?

2. Since the salt water of the sea is a good conductor for electricity, will it pass to the fishes?

3. Will all the living beings of sea be dead?

4. Also what are the electrochemical reactions will be happen on the nearby surfaces of the lightning striking location of the sea?

Answer 1

I have seen lightning hit the middle of a sea lake. ( very happy I had not gone swimming). The water did not boil enough to be observed at my distance, about 500 meters. No dead fish were washed out.

A boat or a head in the sea water will become a focus for the upward streamers that will join the downwards leaders and form a path for the energy of the lightning, and the consequences are the same as on ground for the victims. The good conductivity of the water will disperse the energy over some distance on the surface. I found some numbers on the web:

A typical lightning flash is about 300 million Volts and about 30,000 Amps. In comparison, household current is 120 Volts and 15 Amps. There is enough energy in a typical flash of lightning to light a 100-watt incandescent light bulb for about three months

The following sounds reasonable:

Apparently not, unlike air, the sea is a very good conductor as it contains salt. Rather than creating an direct narrow, path concentrating the "punch", the charge from the lightning strike spreads out sideways and downwards in an expanding half sphere from the surface. Any fish within a few meters of the strike area would probably be killed but beyond that they would probably just feel a tingle. Fish also tend to be a bit deeper in the water and not at the surface where the current is concentrated.

Another entry

At the point of the strike the voltage potential is very high and electrons will dissipate away from that potential. The farther away you get from the strike the the less current there is to dissipate, it drops relatively quickly, it's the surface of a hemisphere equation so it's like a 1/r2 like a drop. As it dissipate the voltage will drop across this hemisphere. The voltage drop across any distance D to delta r, will determine if the current flowing through any objects in the water, and this my friend will determine if you shall survive or not in a lightning strike in the water.

Given these numbers (in my link) and a sea water resistivity of 0.2 ohm meters, you are only guaranteed death via lightning strike if it's closer than 6 meters. It seems that salt water is so conductive current would prefer to flow around you than through you.

Answer 2

The lightning only 'sees'positive and negative charges. If the storm clouds are negatively charged then they drag a positive charge along the surface of the ocean. When the charge reaches a certain capacitance a lighting strike will neutralize the potential. Like some people, the strike follows the path of least resistance; which is usually the highest point. Whether it be a ships mast or you. I have travelled thru such a storm. The lighting and thunder were constant. The magnetic compass was useless. Though grounded, all the electronics were fried. Box of fluorescent bulbs glowed while still in the box. The surface of the ocean drops one foot for every seven miles distant. That being the case I think the curvature would have little effect on the strike.