Te Māramatanga Taketake o te Tikanga Ātete Hikohiko
Ko te tikanga ātete hikohiko he huarahi whenua whānui e whakamahia ana hei tirotiro i ngā āhuatanga o raro i te mata, me te kore e keri. Ka mahi tēnei tikanga mā te whakamahi i te urupare a te toka, te oneone rānei ki te pūngao hiko me ngā mara hikohiko. I roto i te mahi, he tino whai hua tēnei tikanga mō ngā momo hiahia, pērā i te tūhuratanga wai whenua , ngā rangahau kohuke, ngā rangahau poke taiao, me te whakatau i ngā āhuatanga whenua hangarau mō ngā kaupapa hanganga. Kia mārama ai ki tēnei tikanga, he mea nui kia mārama ki ngā ariā taketake o te ātete, te whanaungatanga i waenga i te iahiko hiko me ngā rauemi o raro i te mata, me te whakahaere i ngā inenga i te mara.
Te Ariā o te Ātete me te Aroturuki
Ko te ātete he ine i te kaha o te aukati a tētahi rauemi i te rere o te iahiko. Ko te ātete te tohu o te ρ (rho) ā, he waeine o te ohm-mita (Ωm). Ko tōna taurite ko te kawe hiko (σ), e tohu ana i te kaha o tētahi rauemi ki te kawe hiko, me ngā waeine o te siemens mō ia mita (S/m). He māmā noa iho, ko ngā rauemi he ātete teitei ka uaua ki te kawe i te iahiko (hei tauira, te toka mura maroke), ko ngā rauemi he iti te ātete ka ngāwari ki te kawe i te iahiko (hei tauira, te uku kua whakakiia ki te wai tote).
I roto i te horopaki matawhenua, ko te ātete e whakatauhia ana ehara i te momo toka anake, engari ko te pūngao, te nui o te wai, te taumata mākū, te tote o te wai pūngao, te pāmahana, me te nui o ngā kohuke kawe hiko (pērā i te karāpeti, i ngā whanariki rānei). Nā te mea he maha ngā āhuatanga e pā ana ki ngā uara ātete, me whai whakaaro tonu ki ngā āhuatanga matawhenua o te rohe i te whakamaoritanga raraunga .
Tikanga Ātete Hikohiko Taketake
Ko te kupu "ātete hikohiko" e whakamahia ana hei tohu i ngā tikanga hikohiko e whai ana ki te whakaiti i ngā rerekētanga o te ātete o raro i te mata. Ko te kaupapa matua koia tēnei: ina huri te papa hikohiko i roto i te wā, ka puta he iahiko hiko ki roto i te oneone (ngā iahiko porowhita). Kātahi ka puta he papa aukume tuarua i roto i ēnei iahiko porowhita ka taea te ine mā ngā taputapu. Nā te mea ko te kaha o te iahiko i puta mai e whakawhirinaki ana ki te kawe hiko (te ātete rānei) o te reo, ka taea te whakamahi i te urupare kua tuhia hei whakatau tata i ngā āhuatanga hiko o raro i te mata.
He rerekē tēnei i te tikanga geoheohiko ātete DC, e werohia tika ana te iahiko mā roto i ngā irahiko, ka whakamahia e te tikanga hikohiko te whakapūngao hikohiko—ko te tikanga kāore he pa tika ki te whenua (he iti noa iho rānei te pa). He painga nui tēnei ina rurihia ana i ngā wāhi toka, papa, ngā wāhi rānei he uaua te tāuta i ngā irahiko.
Te Mātāpono o te Whakaoho Hikohiko
Ko te pūtake o te whakapūngao hikohiko i ahu mai i te ture a Faraday, e kī ana ko te panonitanga o te rerenga aukume ka puta he kaha hikohiko (EMF), ka puta he iahiko hiko. I roto i ngā rangahau EM, he tuku hiko kei ngā taputapu e whakaputa ana i tētahi papa aukume tuatahi. Ka uru tēnei papa tuatahi ki te whenua, ka puta he iahiko whakapūngao. Kātahi ka hangaia e te iahiko whakapūngao he papa aukume tuarua ka kitea e te kaiwhiwhi.
Ka taea e te kaiwhiwhi te ine i te kaha o te mara, te āhua (te nekehanga āhua i waenga i ngā tohu tuatahi me te tuarua), ngā mea e rua rānei. Kātahi ka tukatukahia tēnei kaha me ngā mōhiohio āhua hei tawhā pēnei i te kawe hiko kitea, te ātete kitea rānei. Ka kiia ēnei uara he "āhua" nā te mea e tohu ana i ngā toharite whakauru puta noa i te rōrahi o raro i te mata, e pāngia ana e te hohonutanga o te urunga tohu, kaua ki te uara parakore i te pūwāhi kotahi.
Te Hōhonutanga o te Whakauru me te Hōhonutanga o te Kiri
Ko tētahi ariā nui i roto i ngā tikanga hikohiko ko te hohonu o te urunga tohu, e kiia ana ko te "hohonu kiri". Ko te hohonu kiri te hohonutanga āhuatanga e ngoikore ai te kaha o te ngaru hikohiko (ki te 37% o tōna uara tīmatanga). Ka pāngia te hohonu kiri e te ātete o te reo, te auau tohu, me te uruhanga aukume.
I te taha kounga, ka hohonu ake te uru o ngā auau iti, engari he tairongo ake ngā auau teitei ki ngā paparanga papaku. Waihoki, ka taea e te reo ātete ake te uru hohonu atu i te reo kawe hiko. Nō reira, he rautaki nui te whiriwhiri auau i roto i ngā rangahau EM hei whakarite kia kitea ngā ūnga—pērā i ngā puna wai, ngā rohe kua pāngia e te huarere, ngā tinana kohuke rānei—i ngā hohonutanga e tika ana.
Ngā Momo Noa o ngā Tikanga Hikohiko
He maha ngā momo tikanga hikohiko e whakamahia ana i roto i ngā rangahau ātete o raro i te mata:
1. Rohe Auautanga Hikohiko (FDEM)
Ka whakamahia e tēnei tikanga ngā tohu sinusoidal i te kotahi, neke atu rānei ngā auau. He maha ngā wā ka whakamahia ngā taputapu FDEM mō te mahere tere o te kawe hiko papaku, hei tauira, i roto i ngā rangahau poke, mahere uku, rangahau ahuwhenua rānei. Ko ngā raraunga FDEM kei roto i te nuinga o te wā ko ngā wāhanga ā-wāhanga me ngā wāhanga tapawhā e pā ana ki ngā āhuatanga kawe hiko me te aukume o te reo.
2. Rohe Wā Hikohiko (TDEM)
Ka whakamahia e tēnei tikanga he pā o te iahiko ki te tuku hiko, kātahi ka tirohia te pirau o te mara tuarua i muri i te whakawetonga o te tuku hiko. E pā ana ngā mōhiohio wā pirau ki te tohatoha ātete me te hohonu. He pai te TDEM mō te tūhuratanga hohonu atu i te FDEM, pērā i te tūhuratanga hohonu o te wai whenua, ngā rangahau waiariki rānei.
3. Magnetotelluric (MT)
Ka whakamahia e te MT ngā pūtake taiao o ngā rerekētanga o te mara hikohiko mai i te āhuarangi me ngā taunekeneke o te rā me te whenua. He kaha tēnei tikanga mō te ako i te hanganga o te kiri o te Ao i ngā hohonutanga nui, ā, he maha ngā whakamahinga i roto i ngā tūhuratanga waiariki me ngā rangahau tectonic. Mā ngā rerekētanga auau taiao ka taea te whakatau mai i te papaku ki te tino hohonu.
Ahakoa he rerekē ngā pūtake me ngā tikanga ine o ēnei tikanga e toru, kotahi tonu te whāinga matua: kia whiwhi i tētahi tauira ātete o raro i te mata.
Ngā Wāhanga Arotake: Mai i te Hopu ki te Whakamārama
Ko ngā rangahau ātete hikohiko he maha ngā wāhanga. Ko te tuatahi ko te whakamahere: te whakatau i ngā whāinga, ngā hohonutanga o te whāinga, me ngā āhuatanga o te mara, me te whiriwhiri i ngā tikanga me ngā whirihoranga taputapu e tika ana. Ko te tuarua ko te kohikohi raraunga i te mara mā te whakamahi i tētahi tohu, i tētahi tauira ara rānei. I tēnei wāhanga, he mea nui te whakahaere kounga, pērā i te whakahou i ngā inenga, te tuhi i ngā raruraru ahurea (ngā raina hiko, ngā taiapa, ngā paipa whakarewa), me ngā whakatikatika tūranga.
Ko te wāhanga e whai ake nei ko te tukatuka raraunga, tae atu ki te tango haruru, te whakatikatika i te nekenekehanga, te whakawhiti raraunga ki ngā tawhā rūpahu, me te whakaputa whakawhiti-wāhanga, mahere rānei. Kātahi ka mahia te hurihanga hei huri i ngā raraunga ine ki tētahi tauira ātete o raro i te mata e rite ana ki ngā raraunga. Ko te hurihanga te tikanga ka puta he tauira 1D (poutū), 2D (whakawhiti-wāhanga), 3D rānei (rahinga), i runga i te maha o ngā haerenga me te uaua o te ūnga.
Kaua te whakamārama whakamutunga e tū ko ia anake. Ka nui ake te whai tikanga o te tauira ātete ina honoa ki ngā raraunga tautoko pēnei i te matawhenua o te whenua, ngā raraunga keri, ngā inenga matawhenua, me ētahi atu tikanga matawhenua (hei tauira, te ru whenua, te kaha ā-papa rānei). Ka taea e te ātete teitei te tohu i te toka mārō maroke, engari ka taea hoki te tohu i te onepu maroke; ka taea e te ātete iti te tohu i te uku, te wai tote, te whakatōnga kohuke motuhake rānei. Ko te horopaki matawhenua te whakatau i tōna tikanga pono.
Ngā Painga me ngā Here
Ko ngā painga o te tikanga ātete hikohiko ko te tere o te rangahau, te kaha ki te mahi me te kore e pā ki te hikohiko, me te aro nui ki ngā huringa o te kawe hiko e puta mai ana i ngā wai, i ngā kohuke kawe hiko rānei. He tino whai hua hoki tēnei tikanga mō te mahere i ngā wāhi nui.
Heoi anō, kei reira ngā herenga me mārama. Tuatahi, ka taea te whakararuraru i ngā raraunga EM e ngā hanganga tangata pēnei i ngā raina hiko, ngā ara rerewē, ngā waka, me ngā hanganga whakarewa. Tuarua, ka kore e mārama te whakamārama mena kāore i te tautokona e ngā mōhiohio matawhenua. Tuatoru, i roto i ngā pāpāho tino kawe hiko, he iti te hohonu o te urunga, ka uaua te kite i ngā whāinga hohonu. Nō reira, ko te whiriwhiri tikanga, te hoahoa rangahau, me te whakauru raraunga te mea nui ki te angitu.
Te Katinga
Ko te māramatanga taketake mō ngā tikanga ātete hikohiko e ahu mai ana i ngā ariā o te ātete me te whakaawe hikohiko. Mā te tirotiro i te urupare o te mara tuarua nā ngā iahiko i whakaohokia i roto i te mata o raro, ka taea e tātou te whakatau tata i ngā rerekētanga ātete e pā ana ki te āhua o te whenua, te ihirangi wai, me te hanganga whenua. He maha ngā tikanga—FDEM, TDEM, me te MT—e whakarato ana i te ngāwari mai i ngā rangahau papaku ki te hohonu rawa. Ahakoa ngā wero pēnei i te haruru ahurea me te koretake o te whakamaoritanga, he taputapu nui tonu ēnei tikanga i roto i te ahupūngao whenua tono nā te mea ka taea e rātou te mahere tere i te mata o raro, kāore e whakangaro, me te whai kōrero. Ina tika te hoahoa me te whakamaoritanga, ka taea e ngā tikanga ātete hikohiko te whai wāhi nui ki te tūhuratanga rauemi, te whakaiti i te taiao, me te whakamahere whanaketanga.
