There is no widespread tsunami threat in Puerto Rico, different from first reported by some media. However a local threat could be possible. A strong 6.5-magnitude earthquake struck at sea off the Puerto Rican coast at a shallow depth of less than 30 km early on Monday, the US Geological Survey reports.
The quake hit some 56 km off the northern coast of the island. The capital, San Juan, where 400,000 people live is located on the same side of the island.
No immediate injuries or damage has been reported. The tourism industry is extensive on this part of the island. The Pacific Tsunami Warning Center said the quake could trigger a local tsunami, but there is no threat for a widespread tsunami is in place.
The Puerto Rico quake on Monday comes almost exactly 4 years after a powerful 7.0-magnitude quake devastated another Caribbean island – Haiti.
The 2010 disaster took more than 100,000 lives and caused a humanitarian catastrophe in the nation, which remains one of the poorest in the world.
Seismotectonics of the Caribbean Region and Vicinity
Bambance-bambancen da yawa da sarƙaƙƙiya na gwamnatocin tectonic suna kwatanta kewayen farantin Caribbean, wanda ya ƙunshi ƙasa da manyan faranti huɗu (Arewacin Amurka, Kudancin Amurka, Nazca, da Cocos). Yankunan girgizar ƙasa mai zurfi (yankin Wadati-Benioff), ramuka na teku, da tsaunukan tsaunuka suna nuna a sarari raguwar lithosphere na teku tare da tsakiyar Amurka ta Tsakiya da Tekun Atlantika na farantin Caribbean, yayin da girgizar ƙasa a Guatemala, arewacin Venezuela, da Cayman Ridge da Cayman Trench suna nuna kuskuren canji da na'urorin tectonics na kwandon shara.
Tare da gefen arewa na farantin Caribbean, farantin Arewacin Amurka yana motsawa zuwa yamma dangane da farantin Caribbean a saurin kusan 20 mm / yr. Ana ɗaukar motsi tare da manyan kurakuran canji da yawa waɗanda suka shimfiɗa gabas daga Isla de Roatan zuwa Haiti, gami da Laifin Tsibirin Swan da Laifin Oriente. Waɗannan kurakuran suna wakiltar iyakokin kudu da arewa na Cayman Trench. Gabashin gabas, daga Jamhuriyar Dominican zuwa tsibirin Barbuda, motsin dangi tsakanin farantin Arewacin Amurka da farantin Caribbean yana daɗaɗaɗaɗaɗaɗaɗaɗaɗaɗaɗawa kuma yana ɗaukar ɗan lokaci ta kusan kwatankwacin farantin Arewacin Amurka da ke ƙarƙashin farantin Caribbean. Wannan yana haifar da samuwar maɓalli mai zurfi na Puerto Rico da wani yanki na girgizar asa mai zurfi (zurfin kilomita 70-300) a cikin shingen da aka rushe. Ko da yake ana tunanin yankin na Puerto Rico zai iya haifar da girgizar kasa megathrust, ba a sami irin wannan abubuwan ba a cikin karnin da ya gabata. Lamarin da ya faru na ƙarshe a nan ya faru ne a ranar 2 ga Mayu, 1787 kuma an ji shi a ko'ina cikin tsibirin tare da rugujewar ɓarna a duk gabar tekun arewa, gami da Arecibo da San Juan. Tun daga 1900, girgizar asa mafi girma guda biyu da suka faru a wannan yanki sune girgizar kasa ta 4 ga Agusta, 1946 M8.0 Samana a arewa maso gabashin Hispaniola da kuma ranar 29 ga Yuli, 1943 M7.6 Girgizar Mona Passage, dukansu sun kasance girgizar kasa mai zurfi. Wani muhimmin ɓangare na motsi tsakanin farantin Arewacin Amurka da farantin Caribbean a cikin wannan yanki yana ɗaukar nauyin jerin kurakuran yajin aiki na hagu wanda ya raba tsibirin Hispaniola, musamman Laifin Septentrional a arewa da Enriquillo-Plantain. Laifin Lambun a kudu. Ayyukan da ke kusa da Tsarin Lambun Lambun Enriquillo-Plantain ya fi dacewa da mummunan girgizar ƙasa na Janairu 12, 2010 M7.0 Haiti, girgizar ƙasa mai alaƙa da girgizar ƙasa mai kama da ita a cikin 1770.
Komawa gabas da kudu, iyakar farantin yana kewayawa a kusa da Puerto Rico da Arewacin Ƙananan Antilles inda farantin motsi na farantin Caribbean dangane da faranti na Arewa da Kudancin Amurka ba shi da ma'ana, wanda ya haifar da tectonics na tsibiri-arc. Anan, faranti na Arewa da Kudancin Amurka suna karkata zuwa yamma a ƙarƙashin farantin Caribbean tare da Ƙananan Antilles Trench akan ƙimar kusan 20 mm / shekara. Sakamakon wannan ƙaddamarwa, akwai girgizar asa na tsaka-tsaki biyu a cikin faranti da aka rushe da jerin tsaunuka masu ƙarfi a gefen tsibiri. Ko da yake ana ɗaukar ƙananan Antilles ɗaya daga cikin yankuna mafi girgizar ƙasa a cikin Caribbean, kaɗan daga cikin waɗannan abubuwan sun fi M7.0 girma a cikin ƙarni da suka gabata. Tsibirin Guadeloupe ya kasance wurin daya daga cikin manyan girgizar kasa megathrust da suka faru a wannan yanki a ranar 8 ga Fabrairu, 1843, tare da girman girman 8.0. Girgizar kasa mafi girma ta tsakiyar-zurfin kwanan nan da ta afku tare da Ƙananan Antilles arc ita ce girgizar ƙasa ta Martinique a ranar 29 ga Nuwamba, 2007 M7.4 a arewa maso yammacin Fort-De-Faransa.
The southern Caribbean plate boundary with the South America plate strikes east-west across Trinidad and western Venezuela at a relative rate of approximately 20 mm/yr. This boundary is characterized by major transform faults, including the Central Range Fault and the Boconó-San Sebastian-El Pilar Faults, and shallow seismicity. Since 1900, the largest earthquakes to occur in this region were the October 29, 1900 M7.7 Caracas earthquake, and the July 29, 1967 M6.5 earthquake near this same region. Further to the west, a broad zone of compressive deformation trends southwestward across western Venezuela and central Columbia. The plate boundary is not well defined across northwestern South America, but deformation transitions from being dominated by Caribbean/South America convergence in the east to Nazca/South America convergence in the west. The transition zone between subduction on the eastern and western margins of the Caribbean plate is characterized by diffuse seismicity involving low- to intermediate-magnitude (M<6.0) earthquakes of shallow to intermediate depth. The plate boundary offshore of Colombia is also characterized by convergence, where the Nazca plate subducts beneath South America towards the east at a rate of approximately 65 mm/yr. The January 31, 1906 M8.5 earthquake occurred on the shallowly dipping megathrust interface of this plate boundary segment. Along the western coast of Central America, the Cocos plate subducts towards the east beneath the Caribbean plate at the Middle America Trench. Convergence rates vary between 72-81 mm/yr, decreasing towards the north. This subduction results in relatively high rates of seismicity and a chain of numerous active volcanoes; intermediate-focus earthquakes occur within the subducted Cocos plate to depths of nearly 300 km. Since 1900, there have been many moderately sized intermediate-depth earthquakes in this region, including the September 7, 1915 M7.4 El Salvador and the October 5, 1950 M7.8 Costa Rica events. The boundary between the Cocos and Nazca plates is characterized by a series of north-south trending transform faults and east-west trending spreading centers. The largest and most seismically active of these transform boundaries is the Panama Fracture Zone. The Panama Fracture Zone terminates in the south at the Galapagos rift zone and in the north at the Middle America trench, where it forms part of the Cocos-Nazca-Caribbean triple junction. Earthquakes along the Panama Fracture Zone are generally shallow, low- to intermediate in magnitude (M<7.2) and are characteristically right-lateral strike-slip faulting earthquakes. Since 1900, the largest earthquake to occur along the Panama Fracture Zone was the July 26, 1962 M7.2 earthquake.
