Caribbean Tectonic
Total Page:16
File Type:pdf, Size:1020Kb
U.S. DEPARTMENT OF THE INTERIOR Map not approved for release by Director USGS U.S. GEOLOGICAL SURVEY 14 January 2010 t n S i e g s b m Seismicity of thee e E s c aEr p arth 1900 - 2007 N a r e s P l a i n Caribbean Plate and Vicinity Eleuthera A T L A N T I C O C E A N a d New Providence I. ys i e A E K r n G u l f o f M e x i c o ida o d x Compiled by Arthur C. Tarr, Susan Rhea, Gavin Hayes, Antonio Villaseñor, Kevin P. FuKeyr Wlesot ng, anor d Harley Benz r u Fl l o m Cat Island TECTONIC SUMMARY G s F I a r s f l o e a T s a n r i t d o 95° 90° 85° r a 80° t 75° San Salvador 70° 65° 60° S t u S i g s b e e D e e p B g a h Extensive diversity of tectonic regimes characterizes the perimeter of the Caribbean plate, involving no fewer h B A H A M A S a B m Great a than four major adjacent plates (North America, South America, Nazca, and Cocos.) Inclined zones of deep a h -300 -200 -100 0 M e x i c o B a s i n B Exuma a a Long I. m earthquakes (Wadati-Benioff zones), deep ocean trenches, and arcs of volcanoes clearly indicate subduction of Havana n a k I s oceanic lithosphere along the Central American and Atlantic Ocean margins of the Caribbean plate, while Crooked I. l a 0 100 200 300 400 n 0 C a m p e c h e B a n k d s shallow seismicity and focal mechanisms of major shocks in Guatemala, northern Venezuela, and the Cayman Mayaguana I. Acklins I. Ridge and Cayman Trench indicate transform fault and pull-apart basin tectonics. 0 Caicos Is. (U.K.) -100 T U R K S A N D The depth profile panels on this map portray earthquakes that extend from the Middle America Trench axis in Isla de la Caicos C A I C O S I S . ( U . K . ) Juventud Camaguey Bank Turks Island the west to depths as great as 300 km beneath Guatemala, and from the Lesser Antilles Trench axis in the east C U B A PROFILE G -100 to depths of approximately 200 km beneath Guadeloupe and the NE Caribbean. In contrast, seismicity along Merida -200 Grand Inagua the segments of the Caribbean plate margins from Guatemala to Hispaniola and from Trinidad to western Island Silver Bank Venezuela is indicative of transform fault tectonics. Isla Cozumel H i s -200 Santiago p a n i o l G' a T r o u Navidad PROFILE A De Cuba g h Bank Along the northern margin of the Caribbean plate, relative North America moves toward the west at 20° U E R T O R I C O T R E N 20° .K.) 1946 P C H i n Is. (U s man approximately 20 mm/yr, resulting in major transcurrent faults (e.g., Motagua fault in Guatemala) and troughs a Cay -300 B H Grand Cayman Island C BRITISH (e.g., Cayman Trench). Farther east, the North America plate subducts beneath the Caribbean plate resulting in Veracruz n E N h 1943 a R 1946 g VIRGIN Île de la H A I T I u t g e T D O M I N I C A N surface expression of the deep Puerto Rico Trench and a zone of intermediate focus earthquakes in the a i d o ISLANDS (U.K.) R N Gonâve r h c n R E P U B L I C o u g m a A Port-au- T T r u a y M Santo P U E R T O R I C O ( U . S . ) o -300 -200 -100 0 subducted slab. Y C a r Y Prince Domingo r e h n b A o San Juan g m St. Martin C u M o Anguilla (U.K.) S o U.S. VIRGIN (France & Neth. Antilles) J A M A I C A r 0 The plate boundary curves around Puerto Rico and the northern Lesser Antilles where the plate motion vector Villahermosa Kingston T ISLANDS (U.S.) Mona I. a 5 0 of the Caribbean plate relative to the North and South America plates is less oblique, resulting in active island m Vieques (U.S.) S T . K I T T ' S A' u St. Croix Barbuda k Y A N D N E V I S P n arc tectonics. The North and South America plates subduct beneath the Caribbean plate along the Lesser e a St. Kitt's A N T I G U A A N D Turneffe Is. d B H M E X I C O r M U E R T O S T R O U G B A R B U D A -100 Antilles Trench at rates of about 20 mm/yr; consequently, there are both intermediate focus earthquakes within o n L Nevis B o R a t ee Antigua Tuxtla n k e w B E L I Z E o s g G a the subducted South America plate and a chain of active volcanoes along the island arc. s g Gutierrez d rd a n i i R Port-Au Prince I Montserrat (U.K.) Isla de la l s PROFILE F K i la n a n F' Roatán e d t d G u l f o f Alice a g s Guadeloupe -200 e B d The southern Caribbean plate boundary with the South America plate strikes east-west across Trinidad and 1902 B i (France) H o n d u r a s a Shoal 12 January 2010 21:52:09 UTC R n Serranilla k 1 western Venezuela and is characterized by major strike-slip faults (e.g., El Pilar and Boconó faults) and Bank s 0 Marie-Galante 0 B' San Pedro L i g h t n i n g B a n k o e y shallow seismicity, resulting from relative plate motion of about 20 mm/yr. Further to the west, a broad zone Sula g a d 18.451° N., 72.444° W. g G U A T E M A L A 1976 i e D O M I N I C A R a B' g Dominica of convergent deformation trends southwest across western Venezuela and central Columbia. Plate boundaries e p u Depth 10 km d S a i P F R are not well defined across northern South America, but there is a transition from Caribbean/South America Mw = 7 (USGS) 15° s 15° . Martinique e Z s Guatemala n convergence in the east to Nazca/South America convergence in the west, described in more detail below. The . v d H O N D U R A S e i (France) F n A g s 1950 a c C' l Cayos Miskitos d a s transition zone is characterized by high seismic hazard. i I e V e n e z u e l a n B a s i n 20 B S E A d N R p 0 C A R I B B E A Tegucigalpa r e 1902 a r a t e A 0 S T . L U C I A M d w g E e 0 n L n d a d S n i I 2 u A n i L i St. Lucia D n i The Nazca-Caribbean plate boundary offshore of Columbia is characterized by convergence (Nazca plate V s 1942 e a R San A r D D e W a h O a g c L R r d e E Salvador M B G subducting under South America plate) at about 65 mm/yr. The 6 January 1906 Mw = 8.5 megathrust e i T Isla de Providencia p A o 2001 R B A R B A D O S M St. Vincent e g t subduction earthquake occurred on a shallow-dipping interface of this plate boundary segment. The 1906 E s n R ca i n a Barbados e o ua I ns s b N I C A R A G U A d au C Fo a o earthquake occurred in the Colombia-Ecuador region, with a seismic moment (Mo; equivalent to radiated A e B S T . V IT N C E N T aA N D h d N E T H E R L A N D S E e T lfo 30 n b T H E G R E N A D rI N E S T R Go 0 Isla de San Andres i a A N T I L L E S The Grenadines energy) of 6x10**28 dyne-cm (Okal, 1992), and a moment magnitude (Mw) of 8.5 (Tarr and others, 2009.) E 50 b Aruba (Neth.) a N m Islas B C Managua l o B H I. del Maiz Grande o Curaçao Bonaire Los Roques The nucleation point of this earthquake is indicated on the map ( rupture area is from Kanamori and McNally, C (Venez.) Grenada G R E N A D A 1 Isla 1992 L 1982.) 0 a 0 N g Orchilla ic o Isla Blanquilla (Venez.) a d ra e G o l f o d e (Venez.) g u 0 100 200 300 400 a Ve n e z u e l a 1900 Isla La Tortuga Tobago Along the western coast of Central America, the Cocos plate subducts beneath the Caribbean plate at rates of Barranquilla (Venez.) Isla de Margarita (Venez.) 72-81 mm/yr, resulting in a relatively high seismic hazard and a chain of numerous active volcanoes; here C Maracaibo T R I N I D A D A N D C l a r k B a s i n Caracas T O B A G O intermediate-focus earthquakes occur within the subducted Cocos plate to depths of nearly 300 km.