Hasashen girgizar ƙasa

Hasashen girgizar ƙasa reshe ne na kimiyyar geophysics, da farko seismology, wanda ya shafi kimanta yiwuwar girgizar ƙasa gabaɗaya, gami da mita da girman lalacewar girgizar asa a wani yanki na tsawon shekaru ko shekaru.    Duk da yake ana ɗaukar hasashe a matsayin wani nau'in hanta, yawan hasashen girgizar ƙasa yana bambanta da hasashen girgizar ƙasa, hasashen girgizar ƙasa yana ƙididdige yiwuwar girgizar ƙasa a cikin takamaiman lokaci da yanki, yayin da hasashen girgizar ƙasa yayi ƙoƙarin nuna ainihin lokacin, wuri, da girman girgizar da ke gabatowa,[2] wanda ba a iya mantawa da shi ba a halin yanzu.  (1935).  Kagan (1997b, §2.1) ya ce: "Wannan ma'anar tana da lahani da yawa waɗanda ke ba da gudummawa ga rikicewa da wahala a cikin binciken tsinkaya."  Bugu da ƙari ga ƙayyadaddun lokaci, wuri, da girma, Allen ya ba da shawarar wasu buƙatu guda uku: 4) nunin amincewar marubucin a cikin hasashen, 5) damar girgizar ƙasa ta kowace hanya a matsayin abin da ya faru bazuwar, da 6) bugawa a cikin wani nau'i wanda ke ba da kasawa iri ɗaya ganuwa kamar nasarori.  Kagan & Knopoff (1987, shafi na 1563) ayyana hasashen (a wani ɓangare) "zama wani tsari na yau da kullun inda ta wurin samuwan sararin samaniya-lokaci-seismic lokacin girgizar ƙasa da yawa ana yin yarjejeniya sosai…. Dukansu hasashe da hasashen girgizar asa an bambanta su da tsarin gargaɗin girgizar ƙasa, waɗanda, bayan gano girgizar ƙasa, za a iya ba da gargaɗin da za a iya ba da gargadin yankunan da girgizar ƙasa ta shafa.

A cikin shekarun 1970, masana kimiyya sun yi hasashen cewa nan ba da jimawa ba za a sami hanyar da za ta iya yin hasashen girgizar asa, amma a shekarun 1990 ci gaba da gazawar ta sa mutane da yawa su yi tambaya ko ma zai yiwu.  Babban hasashe na nasara na manyan girgizar asa bai faru ba, kuma ƴan da'awar nasara suna da cece-kuce.  Sakamakon haka, an yi amfani da albarkatun kimiyya da na gwamnati da yawa don ƙididdige haɗarin girgizar ƙasa maimakon hasashen girgizar ƙasa.  Ana amfani da irin waɗannan ƙididdiga don kafa ƙa'idodin gini, tsarin ƙimar inshora, shirye-shiryen wayar da kan jama'a da shirye-shiryen, da manufofin jama'a masu alaƙa da abubuwan girgizar ƙasa.  Baya ga hasashen girgizar ƙasa na yanki, irin waɗannan ƙididdigar haɗarin girgizar ƙasa na iya ɗaukar dalilai kamar yanayin yanayin ƙasa.  Ana iya amfani da motsin ƙasa da ake tsammani don jagorantar ƙa'idodin ƙirar gini. 

## Hanyoyi don hasashen girgizar ƙasa
Hanyoyi don hasashen girgizar ƙasa gabaɗaya suna neman yanayi ko tsarin da ke haifar da girgizar ƙasa.  Da yake waɗannan abubuwan na iya zama masu sarƙaƙiya kuma sun haɗa da sauye-sauye da yawa, ana buƙatar manyan dabarun ƙididdiga don fahimtar su, don haka wasu lokuta ana kiran waɗannan hanyoyin ƙididdiga.  Waɗannan hanyoyin suna da ɗan gajeren lokaci, yana mai da su da amfani ga hasashen girgizar ƙasa.

### Elastic rebound
Ko da mafi ƙanƙarar dutsen ba shi da tsauri sosai.  Idan aka ba da ƙarfi mai girma (kamar tsakanin manyan faranti biyu masu girma na tectonic suna wucewa da juna) ɓawon ƙasa zai lanƙwasa ko ya lalace.  Bisa ga ka'idar rebound na Reid (1910), a ƙarshe nakasar (damuwa) ya zama mai girma wanda wani abu ya karye, yawanci a kan wani kuskure.  Zamewa tare da hutu ( girgizar kasa ) yana ba da damar dutsen a kowane gefe don komawa zuwa yanayin da ba shi da kyau.  A cikin wannan tsari, ana fitar da makamashi ta hanyoyi daban-daban, ciki har da igiyoyin girgizar kasa.  Zagayowar ƙarfin tectonic da ke taru a cikin nakasawa na roba kuma a sake shi a cikin kwatsam ana maimaita shi.  Yayin da guguwar girgizar kasa guda daya ta tashi daga kasa da mita daya zuwa kusan mita 10 (ga girgizar kasa ta M 8), bayyanar da kasancewar manyan matsugunan yajin aiki na daruruwan mil yana nuna wanzuwar zagayowar girgizar kasa mai tsawo.

### Girgizar ƙasa ta musamman
Laifin girgizar ƙasa da aka fi nazari (kamar Nankai megathrust, laifin Wasatch, da Laifin San Andreas) sun bayyana suna da sassa daban-daban.  Siffar ƙirar girgizar ƙasa ta nuna cewa girgizar ƙasa gabaɗaya tana takura a cikin waɗannan sassan.  Kamar yadda tsayin da sauran kaddarorin] na sassan ke kayyade, girgizar asa da ke rushe duk kuskuren ya kamata su kasance da halaye iri ɗaya.  Waɗannan sun haɗa da matsakaicin girman (wanda aka iyakance ta tsawon tsattsauran ra'ayi), da adadin adadin da aka tara da ake buƙata don ɓarna ɓangaren kuskure.  Tun da ci gaba da motsin farantin yana sa nau'in ya taru akai-akai, ayyukan girgizar ƙasa a wani yanki ya kamata ya mamaye girgizar asa na halaye iri ɗaya waɗanda ke sake faruwa a ɗan lokaci na yau da kullun.  Don wani yanki na kuskure, gano waɗannan halayen girgizar asa da kuma lokacin sake dawowarsu (ko lokacin dawowa) ya kamata ya sanar da mu game da fashewa na gaba;  wannan ita ce hanyar da aka saba amfani da ita wajen hasashen haɗarin girgizar ƙasa.  Hakanan ana amfani da lokutan dawowa don hasashen wasu abubuwan da ba kasafai suke faruwa ba, kamar guguwa da ambaliya, kuma a ɗauka cewa mita na gaba zai yi kama da mitar da aka gani zuwa yau..

Ƙididdiga daga girgizar ƙasa ta Parkfield ta 1857, 1881, 1901, 1922, 1934, da 1966 sun haifar da hasashen girgizar ƙasar a kusa da 1988, ko kafin 1993 a ƙarshe (a lokacin amincewa da 95%), bisa ga tsarin girgizar kasa. An sanya kayan aiki a cikin fatan gano abubuwan da ke tattare da girgizar ƙasa da ake tsammani. Koyaya, girgizar ƙasa da aka yi hasashen ba ta faru ba sai shekara ta 2004. Rashin nasarar Gwajin tsinkaya na Parkfield ya haifar da shakku game da ingancin tsarin girgizar ƙasa da kansa.

A A wurin hulɗar da faranti biyu na tectonic ke zamewa da juna, kowane sashe dole ne a ƙarshe zamewa, saboda (a cikin dogon lokaci) ba wanda za a bari a baya.  Amma ba duka ba su zame a lokaci guda;  sassa daban-daban za su kasance a matakai daban-daban a cikin sake zagayowar ƙwayar cuta (nakasar) tarawa da sake dawowa kwatsam.  A cikin tsarin gibin girgizar kasa, "babban girgizar kasa na gaba" yakamata a sa ran ba a cikin sassan da girgizar kasa ta baya-bayan nan ta kawar da damuwa ba, amma a cikin tsaka-tsakin tsaka-tsaki inda nau'in da ba a warware shi ya fi girma ba.  Wannan samfurin yana da sha'awar fahimta;  ana amfani da shi a cikin tsinkaya na dogon lokaci, kuma shine tushen jerin tsinkayar daka-Pacific (Pacific Rim) a cikin 1979 da 1989-1991

Koyaya, wasu mahimman zato game da gibin girgizar ƙasa yanzu an san su ba daidai ba ne. Bincike na kusa ya nuna cewa "watakila babu wani bayani a cikin gibin girgizar ƙasa game da lokacin da ya faru ko girman babban abin da ya faru na gaba a yankin";  gwaje-gwaje na kididdigar hasashen kewaye da Pacific ya nuna cewa samfurin rata na girgizar kasa "bai hasashen manyan girgizar ƙasar da kyau ba".  Wani binciken ya kammala cewa dogon lokacin shiru bai kara yiwuwar girgizar kasa ba.

### Sakamakon Makamashi na gaba: Canje-canje na Electromagnetic da Total Electron Count (TEC)
An sami rahotanni masu zaman kansu da yawa kan sauye-sauyen lantarki mai yuwuwa masu alaƙa da girgizar ƙasa.  Amma saboda tsarin tsarin seismogenic mai rikitarwa da ƙarancin fahimtar abubuwan da ke sama, akwai muhawara mai ƙarfi akan siginar lantarki da dangantakarsu da girgizar ƙasa.  Wani bincike na tsawon shekaru goma na canje-canjen filin maganadisu a California daga 2010 zuwa 2020 ya ba da rahoton "... siginar ƙididdiga (shi ne) girman girman girman" sa'o'i 24 zuwa 72 kafin girgizar ƙasa goma sha tara na M 4.5+.  Wani bincike na shekaru goma na bayanan tauraron dan adam Swarm ya ruwaito "An sami muhimmiyar alaƙa tsakanin filin maganadisu da abubuwan da suka faru na TEC da suka gabata kafin aukuwar girgizar ƙasa".  don girgizar ƙasa na M4.0+ kwana ɗaya zuwa bakwai kafin aukuwar girgizar

## Abubuwan da aka sani

Hasashen Rupturewar girgizar ƙasa na California na 2015, Siffa 3, ko UCERF3, shine sabon hasashen fashewar girgizar ƙasa (ERF) ga jihar California, wanda ya maye gurbin UCERF2.  Yana bayar da ƙididdiga masu ƙarfi na yiyuwar da tsananin yiwuwar fashewar girgizar ƙasa a cikin dogon lokaci da na kusa.  Haɗa wannan tare da ƙirar motsi na ƙasa yana samar da ƙididdiga na tsananin girgiza ƙasa da za a iya sa ran a lokacin da aka ba da ita (haɗarin girgizar ƙasa), da kuma barazana ga yanayin da aka gina (hadarin girgizar ƙasa).  Ana amfani da wannan bayanin don sanar da ƙirar injiniya da ka'idodin gini, tsara bala'i, da kimanta ko ƙimar inshorar girgizar ƙasa ta wadatar ga hasarar da za a yi.  Ana iya ƙididdige ma'aunin haɗari iri-iri tare da UCERF3;  Ma'auni na yau da kullun shine yuwuwar girgizar ƙasa M 6.7 (girman girgizar ƙasa na Northridge na 1994) a cikin shekaru 30 (rayuwar al'ada ta jinginar gida) tun daga 2014.

UCERF3 ne ya shirya ta Ƙungiya mai Aiki akan Ƙirar Girgizar Kasa ta California (WGCEP), haɗin gwiwar tsakanin Cibiyar Nazarin Kasa ta Amurka (USGS), California Geological Survey (CGS), da Cibiyar Girgizar Kasa ta Kudancin California (SCEC), tare da gagarumin kudade daga Hukumar Girgizar Kasa ta California (CEA).