Jerin girgizar ƙasa a Philippines

">Philippines tana cikin yankin rikitarwa tsakanin faranti masu yawa, wanda ya haɗa da yankuna masu yawa da kuma babban yanki ɗaya na raguwa, dukansu suna da alaƙa da manyan girgizar ƙasa. Yawancin girgizar ƙasa na intraplate na ƙarami suna faruwa akai-akai saboda hulɗar tsakanin manyan faranti na tectonic a yankin. Girgizar kasa mafi girma a tarihi a Philippines ita ce girgizar kasa ta Celebes Sea ta 1918 tare da girman Mw 8.3.

Yawancin Filipinas suna kwance a cikin yanki na shingen shinge mai ƙarfi na asalin tsibiri, wanda aka sani da Philippine Mobile Belt.  A gabas, farantin Tekun Philippine yana raguwa a ƙarƙashin bel ɗin hannu tare da layin madaidaicin Philippine da mahara na Gabas Luzon a ƙarshen ƙarshen bel.  Haɗin kai a wannan kan iyaka yana da ƙarfi da ƙarfi kuma ɓangaren yajin aiki yana ɗaukar motsi akan tsarin kuskuren Philippine na gefen hagu.  A kudancin Philippines akwai Yankin Molucca Sea Collision Zone, wanda ya shafi gaba da gaba da yankunan da ake karkatar da su zuwa kowane gefen Tekun Molucca.  A yammacin bel ɗin wayar hannu farantin Sunda yana karkata zuwa gabas ƙarƙashin bel ɗin tare da layin Manila, Negros da Cotabato.  A cikin farantin Sunda, ɓacin teku na Tekun Sulu yana raguwa ƙarƙashin Sulu Ridge tare da Sulu Trench.   Farantin Sunda yana ɗauke da sassan Palawan Microcontinental Block, wanda ya yi karo da bel ɗin wayar hannu a ramukan Negros da Cotabato.

Ci gaba da motsi na faranti na tectonic yana haifar da lalacewa mai aiki a cikin belin hannu, kamar a gefen hagu na Cotabato Fault System wanda ke yankewa a fadin Mindanao da kuma gefen dama na Marikina Valley a Luzon.

Yankunan da ke ke da  yawan tsibirin sune tushen yawancin girgizar ƙasa da ta mamaye Philippines. Wannan ya haɗa da ɓarna tare da fasalin farantin da kuma cikin slabs masu raguwa. Ga Trench na Philippines, misalai na waɗanda ke kan fasalin farantin sune abubuwan da suka faru na 1988 Mw 7.3 da M7.6. Girgizar kasa ta 1975 Mw 7.6 ta haifar da lalacewar al'ada ta intra-slab, yayin da 2012 M7.6 ya kasance sakamakon lalacewar turawa a cikin slab mai saukowa.

Yankin Cotabato Trench mai ƙanƙanta ya haɗa da manyan girgizar ƙasa da yawa, gami da girgizar ƙasar Celebes Sea ta 1918 (M8.3), girgizar kasa ta 1976 ta Moro Gulf (M8.0) da girgijin ƙasar Mindanao ta 2002 (M7.5).

 Yana ɗauke da ɓangaren gefen hagu na haɗuwa mai laushi a cikin Philippine Trench, tare da ƙididdigar ƙididdigat na yanzu na 35 ± 4 mm a kowace shekara a kan Leyte, ragewa zuwa arewa zuwa kusan 20 mm a kowace ƙasa a kan Luzon. A Luzon, yankin kuskure ya bazu cikin kurakurai daban-daban, gami da Digdig Fault . Ɗaya daga cikin girgizar ƙasa mafi girma a tarihi a yankin kuskure shine taron Luzon Ms 7.8 na 1990 wanda ya bar kusan mutane 2,000 da suka mutu ko suka bace. Wannan bangare na yankin kuskure ana zaton ya fashe a girgizar kasa ta Luzon ta 1645.  Daga kudu kuskuren ya fashe a lokacin girgizar kasa ta Ragay Gulf ta 1973.&nbsp;&nbsp;&nbsp;

A tsakiyar Mindanao, tsarin kuskuren Cotabato ya ƙunshi cakuda NW-SE da ke faruwa a gefen hagu da SW-NE da ke faruwa na gefen dama. Hudu daga cikin wadannan sun fashe a cikin girgizar kasa ta Cotabato da Davao del Sur ta 2019, kowannensu yana haifar da abubuwan da suka faru tare da girman 6.4 ko mafi girma.

## Hadarin girgizar ƙasa
Idan aka ba da kasancewar manyan wuraren lalacewa a duk faɗin tsibirin, duk wani ɓan*g* na Philippines na iya shafar girgizar ƙasa, ban da wasu sassa na Palawan, inda haɗarin haɗarin girgizar kasa yake da ƙarancin gaske. Babban haɗarin girgizar ƙasa ya fito ne daga raguwar ɓarkewar ɓargo kusa da Manila, Davao da yankunan Cebu. Kuskuren juyawa mai aiki yana da >20 km fadi yankuna na mafi girman saurin ƙasa (PGA) >0.6g (saurin saboda nauyi) don yiwuwar 10% na wucewa (PoE) a cikin shekaru 50, yayin da kuskuren saurin aiki yana da ƙananan yankuna da ke ke kewaye da alamun kuskure a irin wannan matakin. Dukkanin yankunan da ke kusa da yankunan subduction masu aiki suna nuna karuwar haɗari.&nbsp;

A cikin Metro Manila ƙididdi*g* haɗari tana da matsakaicin P*g* na 0.32 *g* don PoE na 10% a cikin shekaru 50. Babban haɗarin ya fito ne daga tushen lalacewa mai zurfi, kamar Marikina Valley Fault System, amma akwai muhimmiyar gudummawa ga haɗarin gaba ɗaya daga yankin Manila zuwa yamma da kuma yiwuwar girgizar ƙasa mai ƙarfi daga girgizar ƙasar da ta samo asali daga Trench na Philippines zuwa gabas. A cikin Metro Cebu, matsakaicin PGA shine 0.32 g don wannan PoE da lokacin. Hadarin ya mamaye yankunan da ba su da zurfi daga wannan yanki na ci gaba da matsawa. Yin amfani da sigogi iri ɗaya Metro Davao yana da darajar mafi girma na 0.45 g. Yankin birni yana zaune kusa da ƙananan kuskuren hagu na hagu na hagu da nau'in baya, kuma waɗannan suna haifar da haɗari mafi girma, kodayake babban gudummawa ya fito ne daga tushe a cikin yankunan Halmahera da Philippine. 

### Lokacin Mutanen Espanya (kafin 1900)

### Karni na 20

### Karni na 21

## Girgizar ƙasa mafi muni