Bayanin Ilimin Lissafi game da Girgizar Ƙasa
Girgizar ƙasa tana ɗaya daga cikin abubuwan da aka fi tattaunawa a kansu a yanayi saboda tasirin da take da shi ga rayuwar ɗan adam. Daga mahangar zahiri, girgizar ƙasa ba wai kawai "girgizar ƙasa ba ne," amma sakamakon sakin kuzarin roba da aka tara a cikin ɓawon duniya. Wannan labarin ya tattauna girgizar ƙasa a cikin harshe mai sauƙin samu, yayin da yake kan ka'idojin kimiyyar lissafi kamar damuwa, damuwa, sassauci, raƙuman ruwa, rawar jiki, da kuma ɓarnar makamashi.
1. Duniya a matsayin tsarin injiniya mai ƙarfi
A zahiri, ana iya kallon Duniya a matsayin babban tsarin injiniya wanda ya ƙunshi layuka: tsakiya, mantle, da ɓawon. An karya ɓawon duniya zuwa faranti na tectonic waɗanda ke "shawagi" akan saman saman mantle (athenosphere). Waɗannan faranti suna motsawa a hankali - yawanci santimita kaɗan ne kawai a kowace shekara - amma wannan motsi mai jinkirin yana haifar da ƙarfi mai yawa saboda girman faranti da kuma babban yankin hulɗa.
Motsin faranti na tectonic yana haifar da tarin damuwa a iyakokin faranti ko lahani a cikin ɓawon. Idan damuwar da ta tara ta wuce juriyar dutsen, fashewar ko canjin kwatsam ta faru. Wannan canjin kwatsam shine abin da muke ji a matsayin girgizar ƙasa.
2. Damuwa, damuwa, da kuzarin roba
Manyan ra'ayoyi guda biyu na kimiyyar lissafi waɗanda suke da matuƙar muhimmanci don fahimtar girgizar ƙasa sune damuwa da damuwa.
– Damuwa ita ce ƙarfin da ke aiki a kowane yanki na abu, naúrarsa ita ce Pascal (Pa).
– Matsi shine canjin da ya shafi siffa ko tsayi saboda damuwa (ba tare da raka'a ba).
Duwatsu a cikin ɓawon duniya na iya zama masu laushi a tsawon lokaci: suna canzawa lokacin da aka yi amfani da ƙarfi kuma suna sake fasalin wani ɓangare lokacin da aka cire ƙarfin. Yayin da faranti ke motsawa, duwatsun da ke kewaye da lahani suna fuskantar matsin lamba. Ana adana makamashin injiniya a matsayin makamashin roba, kamar madaurin roba ko maɓuɓɓugar ruwa mai matsewa.
A taƙaice dai, ƙarfin roba da aka adana yana ƙaruwa tare da ƙaruwar matsin lamba. Idan aka wuce iyakar robar dutse, ba zai iya jure wa matsin lamba ba; gazawa (karyewa) ko zamewa yana faruwa a kan matsalar. A wannan lokacin, ƙarfin robar yana fitowa ba zato ba tsammani a cikin nau'in raƙuman ruwa na girgiza, zafi mai ƙarfi, da kuma nakasa ta dindindin.
3. Kurakurai, ƙarfin gogayya, da kuma tsarin "zamewa daga sanda"
Wani samfurin kimiyyar lissafi da ake amfani da shi wajen bayyana girgizar ƙasa shine zamewa da sanda. Ka yi tunanin tubalan biyu suna matse juna da gogayya. Idan aka tura su a hankali, tubalan ba sa motsawa nan da nan saboda gogayya mai motsi (sanda) tana riƙe su. Ƙarfin turawa yana ci gaba da ƙaruwa har sai ya wuce iyakar gogayya mai ƙarfi, sannan tubalan su zame da sauri (zamewa), suna haifar da girgiza.
Idan aka samu matsala, saman duwatsu suna haɗuwa saboda ƙazanta da kuma matsanancin matsin lamba na yau da kullun. Faranti suna ci gaba da motsi, amma matsalar na iya ci gaba da kasancewa "a kulle" na tsawon shekaru goma zuwa ɗaruruwan shekaru. Idan ya karye, zamewar sauri tana faruwa cikin daƙiƙa kaɗan zuwa mintuna. Wannan zamewar sauri tana haskaka kuzari kamar raƙuman ruwa na girgizar ƙasa.
4. Mayar da hankali, babban ci gaba, da kuma lokacin girgizar ƙasa
Wurin farko da aka fitar da makamashi ana kiransa hypocenter ko focus, wanda shine wurin da ke ƙasa da saman inda matsalar ta fara motsawa. Ana kiran wurin da ke saman duniya kai tsaye sama da abin da aka mayar da hankali. Duk da cewa ana yawan ambaton abin da ke faruwa a cikin labarai, abin da aka mayar da hankali ya fi muhimmanci a zahiri saboda zurfin abin da aka mayar da hankali yana shafar rarraba makamashi da kuma girman lalacewa.
Domin auna "girman" girgizar ƙasa a zahiri, masana kimiyya suna amfani da manufar lokacin girgizar ƙasa, wanda ke da alaƙa da:
- yankin jirgin da ya lalace,
- matsakaicin ƙaura (zamewa)
- taurin dutse.
Lokacin girgizar ƙasa shine tushen ma'aunin girma na zamani (misali, Mw). Ainihin, girma ba wai kawai game da "yadda yake ji ba," amma maimakon haka yawan kuzarin injiniya da ke cikin tsarin fashewa.
5. Raƙuman girgizar ƙasa: Raƙuman P, S, da raƙuman ruwa na saman ƙasa
Makamashin girgizar ƙasa yana yaduwa a matsayin raƙuman girgizar ƙasa. A fannin kimiyyar raƙuman ruwa, waɗannan suna kama da raƙuman ruwa a cikin wani yanayi mai laushi, amma suna da bambancin nau'i saboda yanayin dutsen mai girma uku.
1. Raƙuman P (Babban raƙuman)
Waɗannan raƙuman ruwa suna da tsayin tsayi (faɗaɗawa-matsewa), kamar raƙuman sauti. Suna tafiya da sauri kuma saboda haka suna isa ga seismograph da farko. Raƙuman P na iya tafiya ta cikin daskararru da ruwa.
2. Raƙuman S (Raƙuman biyu)
Raƙuman ruwa masu juyewa (shear) suna da jinkiri fiye da raƙuman ruwa na P. Raƙuman ruwa na S suna tafiya ne kawai ta cikin daskararru, domin ruwa ba zai iya jure wa matsin lamba na shear yadda ya kamata ba. Wannan gaskiyar tana da matuƙar muhimmanci wajen tabbatar da cewa tsakiyar duniya ruwa ne.
3. Raƙuman saman teku (Soyayya da Rayleigh)
Waɗannan raƙuman ruwa suna tafiya kusa da saman Duniya kuma galibi suna haifar da mafi yawan lalacewa saboda girmansu na iya zama mai yawa kuma tsawon lokacinsu yana da tsawo. Raƙuman ruwa na saman ƙasa na iya haifar da rikitattun motsin ƙasa: gefe, hawa, da birgima.
Saurin raƙuman ruwa ya dogara da halayen matsakaicin: yawansu, tsarin roba, da tsarin ƙasa. Saboda haka, wurare biyu daban-daban na iya fuskantar girgiza daban-daban koda kuwa suna da nisan iri ɗaya daga tsakiyar yankin.
6. Ra'ayi da kuma dalilin da yasa gine-gine zasu iya rugujewa
A fannin kimiyyar lissafi, tsarin yana da mitar halitta. Gine-gine ba su bambanta ba. Lokacin da raƙuman girgizar ƙasa suka isa mita kusa da mitar halitta ta gini, amsawar na iya faruwa, wanda hakan zai iya ƙara yawan girgizar ƙasa. Wannan amsawar na iya ƙara ta'azzara lalacewa, musamman a gine-ginen da ba a tsara su don jure girgizar ƙasa ba.
Baya ga sautin, akwai wasu muhimman abubuwa:
- tsawon lokacin girgizar ƙasa (mafi tsayin daka, mafi girman kuzarin da ke shiga cikin ginin),
- matsakaicin hanzarin ƙasa,
- ingancin kayan aiki da ƙirar tsari (misali kasancewar bangon yanke, firam ɗin lokaci, masu raba tushe),
- yanayin ƙasa.
Ƙasa mai laushi kamar ma'adanin ruwa na iya ƙara girgiza (ƙarfafa wurin), yayin da raƙuman ruwa ke raguwa kuma girmansu yana ƙaruwa. Wannan yayi kama da yadda raƙuman ruwa ke tashi yayin da suke shiga ruwa mara zurfi.
7. Ragewar ruwa: lokacin da ƙasa ta "rasa ƙarfi"
Liquefaction misali ne mai ban sha'awa na yadda kimiyyar kayan granular ke taka rawa. A cikin ƙasa mai cike da yashi, girgizar ƙasa na iya ƙara matsin lamba na ruwa a cikin rami, yana sa ƙwayoyin yashi su rasa hulɗa mai tasiri da juna. Sakamakon haka, ƙasa tana aiki kamar ruwa: gine-gine na iya karkata, nutsewa, ko canzawa. Liquefaction yana faruwa ba saboda ƙasa ta koma ruwa ba, amma saboda tasirin da ke riƙe tsarin hatsi ya ragu.
8. Tsunami sakamakon injinan ruwa
Wasu girgizar ƙasa a ƙarƙashin ruwa na iya haifar da tsunami idan suka haifar da matsuguni mai yawa a tsaye a saman teku. A zahiri, tsunami wani dogon raƙuman ruwa ne a cikin teku, tare da tsawon tsayin ɗaruruwan kilomita. A cikin zurfin teku, girmansa ƙanƙanta ne don a iya gano shi cikin sauƙi, amma saurinsa yana da yawa sosai (zai iya zama ɗaruruwan kilomita/h). Yayin da yake kusanto bakin teku, zurfin yana raguwa, saurin yana raguwa, kuma kuzarin yana ƙaruwa, wanda ke haifar da tsayin raƙuman ruwa ya ƙaru sosai.
9. Aunawa da yin kwaikwayon girgizar ƙasa: girgizar ƙasa da kuma kimiyyar juyawa
Ana yin rikodin girgizar ƙasa ta hanyar na'urorin auna girgizar ƙasa, wato na'urorin da ke gano girgizar ƙasa. Ka'idar aikinsu ta dogara ne akan rashin ƙarfin lantarki: taro yana da ikon kiyaye yanayin motsinsa lokacin da ƙasa ke motsawa. Sannan ana nazarin bayanan girgizar ƙasa don tantance wurin girgizar ƙasa, zurfinta, tsarin lahani, da kuma kimanta girmanta.
A cikin ilimin kimiyyar ƙasa na zamani, ana amfani da dabarun juyawa: daga siginar raƙuman da aka yi rikodin, masana kimiyya suna "juya" matsalar kimiyyar lissafi don kimanta tushen girgizar ƙasa da tsarin ƙasa. Wannan ya haɗa daidaiton raƙuman ruwa, ka'idar sassauci, da lissafin lambobi.
10. Kammalawa: girgizar ƙasa a matsayin darasi game da makamashi da raƙuman ruwa
Daga mahangar kimiyyar lissafi, girgizar ƙasa ita ce sakin makamashin roba da aka adana saboda nakasar ɓawon duniya. Wannan makamashin yana canzawa zuwa raƙuman ruwa na girgizar ƙasa waɗanda ke yaɗuwa ta hanyoyi daban-daban, suna hulɗa da tsarin ƙasa, kuma suna shafar gine-gine ta hanyar girgiza, resonance, da hanzarta ƙasa. Fahimtar kimiyyar girgizar ƙasa ba wai kawai ilimin ilimi ba ne: yana ba da tushe mai mahimmanci don rage bala'i, tsara sararin samaniya, da kuma ƙirar gini mafi aminci.
Ta hanyar kimiyyar lissafi, mun fahimci cewa ba za a iya hana girgizar ƙasa ba, amma ana iya rage haɗarinsu. Da zarar mun fahimci yadda Duniya ke adanawa da kuma fitar da makamashi, to, za mu kasance cikin shiri sosai don rayuwa tare da yanayin duniya mai canzawa koyaushe.
