Kunzwisisa kwekutanga nzira dzeaeromagnetic mu geophysics
Nzira yemagetsi inyanzvi yezvepasi inoshandisa kuyera kwemuchadenga kwekuchinja kwesimba remagineti rePasi kuti iongorore mamiriro epasi pevhu. Mukuita, masensa emagetsi anotakurwa nendege kana maherikoputa uye anonyora shanduko musimba remagineti munzira yekuferefeta. Ruzivo urwu runozogadziriswa kuti rwutsanangure kuvapo kwematombo emagineti, maumbirwo ezvepasi, uye miganhu yelithological isingaonekwe zviri nyore kubva pamusoro. Nekuda kwenzvimbo yayo yakakura yekufukidza uye kukurumidza kuwanikwa, aeromagnetism yave nzira yakakosha mukutsvaga zvicherwa, mapping ezvepasi penyika, uye zvidzidzo zve tectonic.
1. Pfungwa huru dzePasi nedombo remagineti
Simba remagineti rePasi rinogona kuonekwa semunda mukuru unobva mukutenderera kwepakati pePasi, pamwe chete nemipiro yekunze kwemunda kubva mukusangana kwemhepo yezuva nemagnetosphere, uye munda usina kujairika unobva mukusiyana kwemagnetization yematombo ari mugomba. Nzira dzemagetsi dzinotarisa pane chikamu chisina kujairika, chinova musiyano uripo pakati pemunda wakayerwa nemunda wekutarisa (kazhinji muenzaniso wemunda mukuru wakaita seIGRF—International Geomagnetic Reference Field).
Matombo anogona kuva nemagnetization nekuda kwezvikamu zviviri: induced magnetization uye remanent magnetization. Induced magnetization inoitika kana matombo akasangana nesimba remagineti rePasi; hukuru hwayo hunoenderana nemagnetic susceptibility yedombo. Matombo eMafic igneous akadai sebasalt kana gabbro anowanzova ne susceptibility yakakura kupfuura matombo e sedimentary, anowanzo gadzira magnetic anomalies yakasimba. Panguva imwecheteyo, remanent magnetization "rekodhi" yemasimba emagineti ekare akachengetwa pakagadzirwa dombo, semuenzaniso apo lava yakatonhorera kupfuura tembiricha yeCurie. Muzviitiko zvakawanda, remanence inogona kuva inotonga uye inokonzera kuti kutungamira kwemagnetization kusaenderane nesimba remagineti rePasi, izvo zvinokanganisa chimiro cheanomaly.
2. Nheyo dzekuongorora kwemhepo
Ongororo dzemuchadenga dzinoyera huwandu hwesimba remagineti (TMI), kana huwandu hwesimba remagineti. Ndege dzinotevera nzira dzakajairwa (mitsetse yekubhururuka) dzine nzvimbo yakatarwa, senge mamita 100–500 ekuongorora kwakadzama, kana 1–2 km yemepu yenzvimbo. Kuwedzera kune mitsetse yekubhururuka, mitsetse yekumonera inowanzoiswa kudzora kuenderana kwedata uye kugadzirisa zvikanganiso zvekusvetuka kana kurongeka.
Kubviswa kwenzvimbo kunokanganisa kugadzikana kwenzvimbo: kubhururuka kwakaderera, kusarongeka kwakanyorwa kwakasimba, asi njodzi dzekuchengetedza uye pesvedzero yenzvimbo yacho inowedzera. Muongororo dzakawanda dzemazuva ano, kukwirira kwekubhururuka kunochengetwa kwakafanana pamusoro penyika (kubhururuka kwakapfava) kuitira kuti pave nedaro rakafanana re sensor kubva pane chinangwa chiri pasi pevhu.
Chishandiso chikuru imagnetometer (semuenzaniso, cesium vapor kana optically pumped magnetometer) inokwanisa kunyora shanduko dzesimba remagineti ne sub-nT accuracy. Sensor inowanzoiswa pa "stinger" pamuswe wendege kana yakasungirirwa kubva muherikoputa kuderedza kupindira kwemagineti kubva mufuselage yendege. Kuwedzera kune magnetometer, sisitimu yekuongorora inosanganisirawo GPS yekuisa nzvimbo, altimeter (radar kana laser) yekukwirira, uye sisitimu yekudzorera kuderedza mhedzisiro yemagineti yendege.
3. Kuwana data uye kugadzirisa zviri nyore
Ruzivo rwemagineti rusina kugadzirwa harugone kududzirwa zvakananga nekuti rune zvinhu zvakasiyana-siyana zvisiri zvepasi. Matanho ekutanga ekugadzirisa anowanzo kusanganisira:
1. Kugadziriswa kwezuva nezuva: Simba remagineti rinochinja nekufamba kwenguva nekuda kwebasa reionospheric nemagnetospheric. Kuti izvi zvigadziriswe, chiteshi chepasi chemagnetometer chinoshandiswa, icho chinoramba chichinyora shanduko dzenguva. Ruzivo rwemhepo runogadziriswa kuti ruenderane nezvakanyorwa pachiteshi chepasi kuti kuderedze mhedzisiro yezuva nezuva.
2. Kubvisa kweIGRF: Munda mukuru wePasi unoverengerwa kubva kuIGRF model zvichienderana nenzvimbo nenguva yeongororo, wobva wabviswa kubva padata rakayerwa kuti uwane magnetic anomaly.
3. Kuripa ndege: Kufamba kwendege, kuchinja kwenzira, uye hunhu hwemagineti hwechimiro chendege zvinogona kuburitsa ruzha. Kuripa kunowanikwa kuburikidza nekuyera kubhururuka uye kutevedzera mupiro wendege kuchiratidzo.
4. Kuenzanisa uye kuenzana: Kuenzanisa kunoenzanisa misiyano pakati pemakwara uchishandisa mitsetse yekusunga, nepo kuenzana kunoderedza "kupatsanura" kana mitsetse yezvigadzirwa zvinoita seyakafanana nemigwagwa nekuda kwemisiyano midiki yasara.
Mhedzisiro yeiyi nzira ipurani yemagineti inosanzwisisika inomiririra zviri nani kusiyana kwemagnetization yematombo ari pasi pevhu.
4. Kuratidzwa kwedata: mamepu nekushandurwa
Ruzivo rwemuchadenga runowanzo ratidzwa semamepu emhando yepamusoro kana mamapu emavara (mamepu eraster) ezvisina kujairika. Zvisinei, kududzira kunoshanda zvakanyanya nekuchinja kwakasiyana-siyana kunoratidza zvinhu chaizvo:
– Kuderedza Kusvika Pamuti (RTP): Kuchinja kunoita kuti peak yeanomaly ive pamusoro chaipo penzvimbo yacho, sekunge ongororo yakaitwa pa magnetic pole (90° inclination). Izvi zvinobatsira kududzira pa latitudes dziri pakati nepakati, asi zvinogona kusagadzikana pedyo ne equator.
- Kuderedza kusvika kuEquator (RTE): Imwe nzira yekuisa latitudes yakaderera, inogadzirisa chimiro cheasina kujairika kuti zvive nyore kuisa mepu.
– First vertical derivative (FVD) nezvimwe zvinobuda: Zvinorodza kusarongeka uye zvinosimbisa miganhu isina kudzika yemaumbirwo akadai sekubatana kwe lithologic kana zvikanganiso.
– Chiratidzo chekuongorora: Chinobatanidza magiradhi akatambanuka uye akatwasuka kuti aratidze mipendero yemanyuko emagineti pasina kuvimba zvakanyanya nekwakanangana nemagineti. Nzira iyi inozivikanwa pakugadzira miganhu yekupinda, madhireki, kana nzvimbo dzekutadza.
– Kuenderera mberi kumusoro/kudzika: Kuenderera mberi kumusoro "kunogadzirisa" data kuti risimbise manyuko akadzika, ukuwo kuenderera mberi pasi kuchivandudza kugadzikana kusina kudzika asi kunonyanya kunzwa ruzha.
Kushandurwa kwacho kunosarudzwa zvichienderana nechinangwa: kungave kuronga mamiriro enzvimbo, kuona zvinangwa zvisina kudzika, kana kufungidzira hudzamu hwenzvimbo yacho.
5. Dudziro yezvepasi uye mashandisirwo makuru
Kududzira kwemhepo kunoenderana nehukama huripo pakati pezvinhu zvisingawanzoitiki uye hunhu hwemagineti hwedombo. Zvinhu zvisingawanzoitiki zvakanyanya zvinowanzobatanidzwa nematombo marefu/ultramafic igneous, kupinda, kana basement yekristalline; nepo zvinhu zvisingawanzoitiki zvishoma zvinogona kuratidza sediment gobvu kana matombo ane mukana mudiki wekukurumidza. Zvisinei, kududzira hakusi nyore sekuti "high = mineral," sezvo remanence, kudzika kwetsime, uye geometry yemuviri wedombo zvinokanganisa zvikuru chiratidzo.
Mashandisirwo akakosha enzira dzemagetsi anosanganisira:
1. Kugadzira mepu ye lithology nemiganhu yemaumbirwo
Kusangana pakati pematombo eigneous nesedimentary, madhike, ma sill, uye zvikanganiso zvinogona kukonzera shanduko mu magnetic contrast. Mapatani e magnetic lineament anowanzo shandiswa kududzira divi renzvimbo dzisina kururama kana nzvimbo dzakatyoka.
2. Kutsvaga zvicherwa
Maitiro emuchadenga anobatsira kuona kupindira kwezvicherwa (semuenzaniso, nickel laterites ine chekuita nemasisitimu eultramafic kana porphyry). Nzira iyi inobatsirawo seongororo yekutanga yekuderedza nzvimbo dzinofungidzirwa usati waita ongororo dzakadzama dzemugungwa.
3. Kutsvaga oiri negasi (kunyanya kugadzira mapa epasi pevhu)
Kunyange hazvo mahydrocarbon asiri magineti, aeromagnetism inogona kuratidza topography yepasi pevhu uye ukobvu hwesediment, izvo zvakakosha pakugadzira magasi.
4. Zvidzidzo zvedunhu nezve geology
Mamepu makuru emagineti anomaly anogona kuratidza miganhu yenyika, divi remabhande ekare emakomo anoputika, uye kunyange zvivakwa zvakakura zveganda.
6. Zvakanakira nezvisingaitwe
Zvakanakira zvikuru zvekuongorora nyeredzi nemagetsi ndezvekumhanya kwayo uye kufukidza kwayo: nzvimbo dzakakura dzinogona kurongwa munguva pfupi kana tichienzanisa nekuongorora pasi. Uyezve, nzira iyi haipindi vanhu uye inogona kusvika kunzvimbo dzakaoma dzakadai semasango akakora, makomo, kana nzvimbo dziri kure.
Zvisinei, pane zvipingamupinyi zvakakosha zvakawanda. Chekutanga, data remagineti harina kujeka (risiri rakasiyana): kusanganiswa kwakasiyana kwekudzika kwetsime, chimiro, uye magnetization kunogona kuburitsa zvinhu zvisina kujairika zvakafanana. Nokudaro, kududzira kunofanirwa kubatanidzwa nedzimwe data dzakadai se field geology, gravity, radiometry, kana drilling. Chechipiri, ruzha rwetsika dzakadai semagetsi, mapaipi, njanji, uye zvivakwa zvesimbi zvinogona kuburitsa zvinhu zvisina kujairika zvisiri zve geology. Chechitatu, munzvimbo dzakaderera, chimiro chezvinhu zvisina kujairika chinowanzova chisina kuenzana, chinoda shanduko dzakakosha uye kududzirwa kwakanyatsonaka.
7. Kufamba kuri nyore kubva pakuongorora kusvika kune chinangwa
Muchidimbu, kufamba kwemhepo kunogona kunzwisiswa se: kuronga nzira (nzvimbo uye kukwirira kwekubhururuka) → Kuwanikwa kwedata reTMI uye kufamba → kugadziriswa kwezuva nezuva, IGRF, muripo → kuenzana uye kuenzana kwezvikamu → kugadzirwa kwemepu isina kujairika → kushandurwa (RTP/RTE, zvinotorwa, chiratidzo chekuongorora) → dudziro yechimiro uye lithological → kuenzanisa kwehuwandu (semuenzaniso kufungidzira kudzika) → kubatanidzwa nedzimwe data rejiyoloji kuti pave nekutsvaga chinangwa.
Mhedziso
Nzira yemagetsi inyanzvi inoshanda ye geophysical yekuchinja-chinja kwemapu emagetsi epasi pevhu nekukurumidza uye zvakanyanya. Nekunzwisisa pfungwa huru dzesimba remagetsi rePasi, hunhu hwemagetsi ematombo, matanho ekugadzirisa data, uye matekiniki ekushandura nekududzira, tinogona kushandisa aeromagnetism kune zvinangwa zvakasiyana-siyana - kubva kumepu yejiyoroji yenzvimbo uye kuzivikanwa kwechimiro kusvika pakutsigira kutsvaga zvicherwa uye mepu yebasement. Pasinei nekusakwana kwayo nekuda kwekududzira kwayo kusiri kwakasiyana, aeromagnetism inoramba iri imwe yenzira dzinonyanya kukosha kana ikabatanidzwa nedzimwe data rejiyoroji nerejiyoroji.
Kana muchida, ndinogona kugadzirisa chinyorwa ichi kuti chienderane nemamiriro ezvinhu eIndonesia (semuenzaniso, mienzaniso yenzvimbo dzemakomo anoputika, ultramafic muSulawesi, kana mabheseni makuru e sedimentary) kana kuwedzera bibliography nemifananidzo yemafambiro ekugadzirisa data.
