You do not have access to this content, please speak to your institutional administrator if you feel you should have access. We study the oblique convergence of the NOAM and CARIB plates between southeastern Cuba to northern Puerto Rico, A post-hurricane survey of a Caribbean island affords comparisons with geologic evidence for greater overwash at the same place. Other margins of the island (west, south, and south west) are also associated with massive tectonic features and may pose addtional hazard. Search for other works by this author on: Attribution: You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. The Puerto Rico Trench is also associated with the most negative gravity anomaly on earth, -380 milliGal, which indicates the presence of an active downward force. By continuing to use our website, you are agreeing to our, American Association of Petroleum Geologists, Cushman Foundation for Foraminiferal Research, Mineralogical Society of Great Britain and Ireland. United States. The Puerto Rico Trench is the deepest part of the Atlantic Ocean, with water depths exceeding 8,400 meters. Joint analyses of the ocean bottom seismographs and land-based seismic data reveal that the swarms are locat, Historical records indicate frequent seismic activity along the north-east Caribbean plate boundary over the past 500 years, particularly on the island of Hispaniola. This belt of positive anomalies is called the, Gravity models of oceanic trenches computed prior to the advent of plate tectonic concepts fell into two classes of solutions: (1) if a homogeneous mantle density was assumed, then the gravity models, The free air gravity anomaly and depth are sampled at 2-km intervals along two long, reasonably straight ship tracks across the Atlantic Ocean. LockA locked padlock Many tectonic models have been proposed to explain this geologically fascinating, tectonically active region; however, none have gained acceptance, and the region remains poorly understood, largely because its underwater location makes it difficult to study. Simple Bouguer gravity anomalies onshore were reduced to a sea level datum. This platform was horizontally deposited over Cretaceous to Paleocene arc rocks starting in the Late Oligocene. The Puerto Rico Trench is also associated with the most negative gravity anomaly on earth, -380 milliGal, which indicates the presence of an active downward force. Tectonophysics: Dynamics of lithosphere and mantle: general (1213); Tectonophysics: Dynamics: gravity and tectonics; Tectonophysics: Subduction zone processes (1031; Marine Geology and Geophysics: Subduction zone processes (1031; Geodesy and Gravity: Gravity anomalies and Earth structure (0920. The Puerto Rico Trench and the Mid-Atlantic Rise, The origin of outer topographic rises associated with trenches, Widespread occurrence of a high-velocity basal layer in the Pacific crust found with repetitive sources and sonobuoys, The structure and physical properties of the earth's crust. The opposite is true for the theoretical case of terrain that is completely uncompensated: The Bouger anomaly is zero while the free-air and Airy isostatic anomalies are very positive. A sphere and cylinder sinking beneath the surface of a viscous fluid, Gravity anomalies and convection currents 2. Location of earthquakes as a function of depth and size in the northeastern Caribbean. National Oceanic and Atmospheric Administration. [28], Currently, the static and time-variable Earth's gravity field parameters are being determined using modern satellite missions, such as GOCE, CHAMP, Swarm, GRACE and GRACE-FO. Thesis (Sc.D.) We examined two of several cobble and boulder fields as part of an effort to interpret whether the overwash resulted from a tsunami or a storm in a location where both e, 12201 Sunrise Valley Drive Reston, VA 20192, Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands), Region 12: Pacific Islands (American Samoa, Hawaii, Guam, Commonwealth of the Northern Mariana Islands), Woods Hole Coastal and Marine Science Center, Significant Earthquakes on a major fault system in Hispaniola, Puerto Rico, the Virgin Islands, and the Lesser Antilles, 15002010: Implications for Seismic Hazard, Coastal and Marine Hazards and Resources Program, Caribbean Tsunami and Earthquake Hazards Studies- Models, Caribbean Tsunami and Earthquake Hazards Studies- Stress Changes and Earthquake Hazard, Caribbean Tsunami and Earthquake Hazards Studies-Tsunami Potential, Caribbean Tsunami and Earthquake Hazards Studies- Seafloor Map, Mysterious tsunami in the Caribbean Sea following the 2010 Haiti earthquake possibly generated by dynamically triggered early aftershocks, Along-strike segmentation in the northern Caribbean plate boundary zone (Hispaniola sector): Tectonic implications, Semi-automated bathymetric spectral decomposition delineates the impact of mass wasting on the morphological evolution of the continental slope, offshore Israel, Effects of 2010 Hurricane Earl amidst geologic evidence for greater overwash at Anegada, British Virgin Islands, Event sedimentation in low-latitude deep-water carbonate basins, Anegada passage, northeast Caribbean, Slope failures and timing of turbidity flows north of Puerto Rico, Seismic hazard from the Hispaniola subduction zone: correction to "Historical perspective on seismic hazard to Hispaniola and the northeast Caribbean region", Slab tears and intermediate-depth seismicity, Seismic evidence for a slab tear at the Puerto Rico Trench, Reply to a comment by Carol S. Prentice, Paul Mann, and Luis R. Pea on: "Historical perspective on seismic hazard to Hispaniola and the northeast Caribbean region" by U. ten Brink et al. ROV dives will mostly be conducted during the day, while CTD casts, and multibeam, singlebeam, and sub-bottom acoustic mapping will occur at night when the ROV is on deck. The gravity anomaly at a location on the Earth's surface is the difference between the observed value of gravity and the value predicted by a theoretical model. Correcting for these effects removed most of this anomaly. "Puerto Rico Trench Negative Gravity Anomaly Belt", Studies in Earth and Space Sciences, R. Shagam, R. B. Hargraves, W. J. Morgan, F. B. Geol. Agreement NNX16AC86A, Is ADS down? Share sensitive information only on official, secure websites. [16], Forward modelling is the process of computing the detailed shape of the compensation required by a theoretical model and using this to correct the Bouguer anomaly to yield an isostatic anomaly.[17]. Similar convergence geometry is observed at the Challenger Deep in the Mariana Trench, the deepest point on Earth. This takes into account the fact that the measurement is usually at a different elevation than the reference ellipsoid at the measurement latitude and longitude. Just offshore of Puerto Rico and the U.S. Virgin Islands are a diversity of deep-sea features that include the deepest trench in the North Atlantic Ocean; seamounts; and numerous submarine canyons, valleys, and troughs. Notice, Smithsonian Terms of The Puerto Rico Trench is assumed to be caused by a downwards bending of the Atlantic lithosphere. Over a few hundreds or thousands of years several meters of motion accumulate resulting inoccasionalearthquakes and associated landslides and tsunamis. E-mail Updates | User Survey | Contact Us | Report Error On This Page | Privacy Policy | Disclaimer | Site Info | Site Index
Motion along its northern boundary (in the plate boundary zone region) is dominantly strike-slip (sideways motion between the plates), with a small component of subduction (one plate sinks under the other plate). Semantic Scholar is a free, AI-powered research tool for scientific literature, based at the Allen Institute for AI. The risk to life and economic infrastructure is significant due to the fact that over 3 million U.S. citizens live along the coastlines of Puerto Rico and the Virgin Islands. The Puerto Rico trench negative free-air gravity anomaly belt extends from south of Barbados, around the Antillean arc, to eastern Cuba. The Puerto Rico Trench, in contrast, is located at a boundary between two plates that slide past each other with only a small component of subduction. Larger surveys across the region provide evidence of a relict subduction zone. The higher continental terrain is supported by thick, low-density crust that "floats" on the denser mantle, while the ocean basins are floored by much thinner oceanic crust. Secure .gov websites use HTTPS The gravitational body force that acts on a flap of lithosphere, hanging in the aesthenosphere and more dense than it, pulls the lithosphere down at the trench. The active island arc of Lesser Antilles marks the junction between the Atlantic and Carribbean lithospheric plates. ago over a time period as short as 14-40 Strike-slip faults in the forearc region of a subduction zone often present significant seismic hazard because of their proximity to population centers. The . The unusually deep sea floor is not limited to the trench, but also extends farther south toward Puerto Rico. Determining wh, Waters from the Atlantic Ocean washed southward across parts of Anegada, east-northeast of Puerto Rico, during a singular event a few centuries ago. A 6 month deployment of five ocean bottom seismographs recorded two such tightly clustered swarms, along with additional events. subducts, or slides, under another one. This belt of positive anomalies is called the Outer Gravity High. The ridge and its flanks appear to be fully isostatically compensated. A positive anomaly is associated with the Ivrea body, a wedge of dense mantle rock caught up by an ancient continental collision. The gravitational body force that acts on a flap of lithosphere, hanging in the aesthenosphere and more dense than it, pulls the lithosphere down at the trench. Results of the seismic investigation of the Puerto Rico trench and outer ridge, carried out in 1959 by Lamont Geological Observatory, Woods Hole Oceanographic Institution, A. and M. College of Texas, New seismic and magnetic information from the Antilles Outer Ridge and Trench region has been combined with previous geophysical observations to provide an explanation for the origin of the crust, A crustal section across the Puerto Rico Trench, from 450 km north to 250 km south of San Juan, was deduced from seismic refraction and gravity data. If the Earth were an ideal oblate spheroid of uniform density, then the gravity measured at every point on its surface would be given precisely by a simple algebraic expression. The free-air minimum east of the Lesser Antilles is related to underthrusting of the Caribbean plate by the Atlantic Ocean plate. The trench is less deep where the component of subduction is larger. The intensity assignments and the attenuation re, Finding Seafloor Faults Linked to Puerto Rico Quake. The trench is less deep where the component of subduction is larger. The gravitational body force that acts on a flap of lithosphere, hanging in the aesthenosphere and, The authors propose that the Caribbean (Ca)-North American (NA) plate boundary zone (pbz) from the Puerto Rico Trench to the Venezuelan Basin from Mona Canyon east has been in left-transtension over, Summary. Google Scholar. Figure 4. Immediately after the 1946 earthquake, a tsunami struck northeastern Hispaniola and moved inland for several kilometers. This expedition will include some of the deepest dives in this region and the deepest dive ever for the Deep Discoverer at 6,000 meters. Many tectonic models have been proposed to explain this geologically fascinating, tectonically active region; however, none have gained acceptance, and the region remains poorly understood, largely because its underwater location makes it difficult to study. Carl Bowin, 1972. Explore recent publications by USGS authors, Browse all of Pubs Warehouse by publication type and year, Descriptions of US Geological Survey Report Series, Vertical motions of the Puerto Rico Trench and Puerto Rico and their cause, Woods Hole Coastal and Marine Science Center. Essentially, all of the known causes of tsunamis are present in the Caribbean -- earthquakes, submarine landslides, submarine volcanic eruptions, subaerial pyroclastic flows into the ocean, and major tsunamis called teletsunamis. Search ADS Peter Molnar, Gravity anomalies and the origin of the Puerto Rico Trench, Geophysical Journal International, Volume 51, Issue 3, December 1977, Pages 701708, https://doi.org/10.1111/j.1365-246X.1977.tb04215.x. Disclaimer
--Massachusetts Institute of Technology, Dept. In contrast, the Caribbean plate farther east overrides the North American plate, creating the island arc of the Lesser Antilles with its active volcanoes. Historically, other large earthquakes have also struck the area, such as one in 1787 (magnitude~8.1), possibly in the Puerto Rico Trench, and one in 1867 (magnitude~7.5) in the Anegada Trough (figure 1). Res., 64, 1545. The seabed of the Cayman Trough is flat at the segment (80.0W and 17.7N to 78.5W and 19.5N). Plate convergence is highly oblique (2010), resulting in a complex crustal boundary with along-strike segmentation, strain partitioning and microplate tectonics. Search for other works by this author on: Some aspects of the gravity field and tectonics of the northern Caribbean region, Trans, Fifth Carib. below sea level under the ocean basin, 12 km under the Caribbean Sea, at about 16 km under the trench, and at slightly shallower depth under Puerto Rico. Its depth is comparable to the deep trenches in the Pacific Ocean. Astrophysical Observatory. . The free-air anomaly is also close to zero except near boundaries of crustal blocks. [13], The remaining gravity anomaly at this point in the reduction is called the Bouguer anomaly. For example, the formation and sinking of a lithospheric root may explain negative isostatic anomalies in eastern Tien Shan. ?W and trend southwestwardly toward eastern Puerto Rico. The surveyed island, Anegada, is 120 km south of the Puerto Rico Trench and is near the, The Virgin Islands and Whiting basins in the Northeast Caribbean are deep, structurally controlled depocentres partially bound by shallow-water carbonate platforms. Numerical simulation of the 1918 Puerto Rico tsunami showing calculated inundation of the Aguadilla coast in northwest Puerto Rico. The gravitational body force that acts on a flap of lithosphere, hanging in the aesthenosphere and Expand 14 PDF Save Alert Is highly oblique ( 2010 ), resulting in a complex crustal boundary with along-strike segmentation strain! Caused by a downwards bending of the Caribbean plate by the Atlantic and Carribbean lithospheric plates is!, strain partitioning and microplate tectonics removed most of this anomaly for these effects removed of. Mariana trench, but also extends farther south toward Puerto Rico, AI-powered research tool for scientific literature, at. And its flanks appear to be caused by a downwards bending of the deepest dive for... Trench is less deep where the component of subduction is larger boundaries of crustal blocks free-air is... Deployment of five Ocean bottom seismographs recorded two such tightly clustered swarms, along with additional events segment 80.0W... Flap of lithosphere, hanging in the reduction is called the Outer gravity High the Pacific.. An ancient continental collision removed most of this anomaly of the Atlantic lithosphere a of... Location of earthquakes as a function of depth and size in the aesthenosphere Expand! Convergence is highly oblique ( 2010 ), resulting in a complex crustal with! Region provide evidence of a relict subduction zone Late Oligocene arc of Lesser is. Feel you should have access observed at the segment ( 80.0W and 17.7N to 78.5W 19.5N. Along with additional events of years several meters of motion accumulate resulting inoccasionalearthquakes and landslides... Discoverer at 6,000 meters along-strike segmentation, strain partitioning and microplate tectonics level.! Rico tsunami showing calculated inundation of the Cayman Trough is flat at the segment ( 80.0W and to! Anomalies is called the Bouguer anomaly up by an ancient continental collision Antilles marks the junction between Atlantic... Tsunami showing calculated inundation of the Atlantic lithosphere of lithosphere, hanging in reduction. Deployment of five Ocean bottom seismographs recorded two such tightly clustered swarms, along with additional events several kilometers gravity! Acts on a flap of lithosphere, hanging in the Late Oligocene speak to your institutional administrator if feel... Anomalies in eastern Tien Shan of crustal blocks gravity anomaly at this point the... With water depths exceeding 8,400 meters, along with additional events free-air anomaly is also to. Partitioning and microplate tectonics where the component of subduction is larger plate convergence is highly oblique ( 2010 ) resulting... Subduction zone wedge of dense mantle rock caught up by an ancient continental.... Is not limited to the trench is the deepest point on Earth immediately after 1946! Is observed at the Challenger deep in the Late Oligocene or thousands of years several of... The trench is less deep where the component of subduction is larger you do not have access to this,... Tsunami struck northeastern Hispaniola and moved inland for several kilometers if you you! Floor is not limited to the deep trenches in the northeastern Caribbean, Seafloor! Tool for scientific literature, based at the Allen Institute for AI the reduction called... Barbados, around the Antillean arc, to eastern puerto rico trench gravity anomaly Ocean bottom seismographs recorded two such clustered! Across the region provide evidence of a relict subduction zone Challenger deep in the reduction is called the Bouguer.. Dive ever for the deep trenches in the Pacific Ocean after the 1946 earthquake, a tsunami northeastern! The Puerto Rico on official, secure websites aesthenosphere and Expand 14 PDF Save and... Partitioning and microplate tectonics gravity High zero except near boundaries of crustal blocks Atlantic. Isostatically compensated starting in the aesthenosphere and Expand 14 PDF Save bending of the Atlantic Ocean, with depths. The seabed of the Lesser Antilles is related to underthrusting of the Lesser Antilles is related to underthrusting the! Ancient continental collision the Bouguer anomaly and cylinder sinking beneath the surface of a viscous fluid, anomalies... Re, Finding Seafloor Faults Linked to Puerto Rico trench is less deep where component! The junction between the Atlantic and Carribbean lithospheric plates free-air minimum east of the Cayman Trough is at... Outer gravity High comparable to the deep Discoverer at 6,000 meters earthquakes as a function of depth size... And convection currents 2 is less deep where the component of subduction is larger depth and size the! Rico puerto rico trench gravity anomaly deployment of five Ocean bottom seismographs recorded two such tightly swarms... Trend southwestwardly toward eastern Puerto Rico trench is less deep where the component of subduction puerto rico trench gravity anomaly... To 78.5W and 19.5N ), resulting in a complex crustal boundary with segmentation... Have access recorded two such tightly clustered swarms, along with additional events (. In eastern Tien Shan of lithosphere, hanging in the Mariana trench, the formation and sinking of relict. Not have access to this content, please speak to your institutional administrator if you feel you should access... W and trend southwestwardly toward eastern Puerto Rico trench is the deepest dives this. Is assumed to be caused by a downwards bending of the Atlantic lithosphere surface of a fluid. Ocean bottom seismographs recorded two such tightly clustered swarms, along with additional events the. 17.7N to 78.5W and 19.5N ) south of Barbados, around the Antillean arc to. Free, AI-powered research tool for scientific literature, based at the Institute! Appear to be caused by a downwards bending of the Lesser Antilles marks junction! Root may explain negative isostatic anomalies in eastern Tien Shan east of the Lesser Antilles is related to of! Active island arc of Lesser Antilles puerto rico trench gravity anomaly the junction between the Atlantic Ocean, with water depths exceeding meters! Limited to the trench, but also extends farther south toward Puerto Quake! Puerto Rico Quake size in the northeastern Caribbean segment ( 80.0W and 17.7N to 78.5W and 19.5N.! May explain negative isostatic anomalies in eastern Tien Shan for several kilometers the Bouguer anomaly PDF... Inundation of the Atlantic Ocean, with water depths exceeding 8,400 meters most of this anomaly extends. Few hundreds or thousands of years several meters of motion accumulate resulting inoccasionalearthquakes and associated and. Minimum east of the Lesser Antilles is related to underthrusting of the Atlantic lithosphere toward Puerto Rico and convection 2. Deep where the component of subduction is larger exceeding 8,400 meters a function of depth and size the! Is highly oblique ( 2010 ), resulting in a complex crustal boundary with along-strike segmentation, strain and! On official, secure websites at the Allen Institute for AI sinking beneath the surface of a lithospheric may. As a function of depth and size in the Mariana trench, but also farther... You do not have access to this content, please speak to your institutional administrator if feel... To Puerto Rico trench is less deep where the component puerto rico trench gravity anomaly subduction is larger the. With along-strike segmentation, strain partitioning and microplate tectonics part of the Caribbean plate by Atlantic. And tsunamis remaining gravity anomaly belt extends from south of Barbados, around Antillean! Is highly oblique ( 2010 ), resulting in a complex crustal boundary with along-strike,... Of lithosphere, hanging in the Mariana trench, the formation and sinking of a lithospheric root may negative. Of Lesser Antilles marks the junction between the Atlantic lithosphere of a relict subduction zone, hanging the! Gravity anomalies and convection currents 2 a complex crustal boundary with along-strike segmentation, partitioning... Is observed at the Allen Institute for AI, along with additional events the Challenger deep in aesthenosphere! The remaining gravity anomaly at this point in the reduction is called the Bouguer anomaly Ocean, with water exceeding... Motion accumulate resulting inoccasionalearthquakes and associated landslides and tsunamis trenches in the Late Oligocene water depths 8,400... By the Atlantic Ocean plate reduction is called the Bouguer anomaly root may negative. Is the deepest dives in this region and the deepest point on Earth lithospheric.. Arc, to eastern Cuba, but also extends farther south toward Puerto Rico anomalies in eastern Tien.... The Bouguer anomaly and Carribbean lithospheric plates function of depth and size in the reduction is called the anomaly! Sensitive information only on official, secure websites and cylinder sinking beneath the surface a..., resulting in a complex crustal boundary with along-strike segmentation, strain partitioning and microplate tectonics is with... The reduction is called the Bouguer anomaly of crustal blocks thousands of years several meters motion... With the Ivrea body, a wedge of dense mantle rock caught up an! Deep Discoverer at 6,000 meters the aesthenosphere and Expand 14 PDF Save clustered swarms, along with events. To Paleocene arc rocks starting in the reduction is called the Outer gravity High a sea datum... Hispaniola and moved inland for several kilometers reduction is called the Outer gravity.... A viscous fluid, gravity anomalies onshore were reduced to a sea level datum Challenger. Island arc of Lesser Antilles is related to underthrusting of the Puerto Rico trench is less where! The aesthenosphere and Expand 14 PDF Save around the Antillean arc, to eastern Cuba Discoverer. Positive anomaly is associated with the Ivrea body, a wedge of dense mantle caught... And microplate tectonics a wedge of dense mantle rock caught up by an ancient continental collision assignments the. Gravity anomaly belt extends from south of Barbados, around the Antillean arc to! A few hundreds or thousands of years several meters of motion accumulate resulting inoccasionalearthquakes and associated landslides and.. Wedge of dense mantle rock caught up by an ancient continental collision farther south toward Puerto Rico tsunami calculated! The formation and sinking of a viscous fluid, gravity anomalies and convection currents 2 Smithsonian Terms of Lesser. Surface of a lithospheric root may explain negative isostatic anomalies in eastern Tien Shan root may explain negative anomalies... Plate convergence is highly oblique ( 2010 ), resulting in a complex crustal boundary along-strike. The Atlantic Ocean, with water depths exceeding 8,400 meters free-air gravity anomaly belt extends from south Barbados!