In a relatively large number of cases it is probably only the result of currents, which were carried over the earth's surface, whether due to reduced resistance caused by cultivation, or completely chaotic, due to an excessive surplus of electric charge from lightning in the surveyed site.
Katika idadi kubwa ya kesi Relativt pengine ni matokeo ya mikondo tu, ambayo ililetwa uso wa dunia, Kama kutokana na upinzani Kupunguza Husababishwa na kilimo, au kabisa chaotic, kutokana na ziada ya malipo ya umeme Utokaji kutoka umeme katika utafiti tovuti.