Finally, in some cases they may follow various underground archeological (also geological or industrial) structures, which would otherwise without the contribution of electricity show either a significantly lower intensity, only minimal or not at all.
Sa wakas, sa ilang mga kaso ay maaaring Sila sundin ang iba't-ibang underground arkeolohiko (din geological o pang-industriya) kaayusan, Aling Gusto Kung hindi walang-ambag ng koryente Alinman ipakita ang isang makabuluhang mas mababang intensity, minimal lamang o hindi sa lahat.