The Mona Passage () is a

strait A strait is a water body connecting two seas or water basins. The surface water is, for the most part, at the same elevation on both sides and flows through the strait in both directions, even though the topography generally constricts the ...

that separates the islands of

Hispaniola Hispaniola (, also ) is an island between Geography of Cuba, Cuba and Geography of Puerto Rico, Puerto Rico in the Greater Antilles of the Caribbean. Hispaniola is the most populous island in the West Indies, and the second-largest by List of C ...

and

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

. The Mona Passage connects the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

to the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

and is an important shipping route between the Atlantic and the

Panama Canal The Panama Canal () is an artificial waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a Channel (geography), conduit for maritime trade between th ...

. The Mona Passage is long. It is fraught with variable tidal currents created by large islands on either side of it, and by sand banks that extend out from both coasts.

Islands

There are three small islands in the Mona Passage: * Mona Island lies close to the middle of the Mona Passage. * northwest of Mona Island is the much smaller Monito Island. * northeast of Mona Island and much closer () to the Puerto Rican mainland is Desecheo Island.

Structure and seismicity

The Passage was the site of a devastating earthquake and tsunami that hit western Puerto Rico in 1918.http://soundwaves.usgs.gov/2007/05/ Uri ten Brink, ''New Bathymetric Map of Mona Passage, Northeastern Caribbean, Aids in Earthquake- and Tsunami-Hazard Mitigation,'' USGS Sound Waves Newsletter, May 2007 It is the site of frequent small earthquakes. The passage is underlain by a seismically active

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...

zone that overprints an older, partly eroded tilted-block structure. Desecheo Island sits on the Desecheo ridge, a narrow east-west ridge that extends west from the northwest corner of Puerto Rico. The ridge forms the southern boundary of the Mona Canyon, which extends toward the north into the Puerto Rico Trench. The east face of the rift has a sharp relief of and is controlled by the north-south-trending Mona Rift Fault. The epicenter of the 1918 earthquake was located along the east or southeast edge of the Mona Rift.

Physical oceanography

The Mona Passage connects the

waters and

waters, above a sill depth of . The sill runs along a northwest to the southeast direction between Cabo Engaño in Hispaniola in the west and the Cabo Rojo Shelf in Puerto Rico to the east margin of the Mona Passage. The vertical profile of the low-frequency (periods longer than 2 days) mean meridional water transport is characterized by a two-layer structure. The upper layer lies above a depth of , with the upper water masses, the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

Surface Water, Subtropical Underwater and Sargasso Sea Water entering the Caribbean Sea from the Atlantic Ocean. Below this layer, the Tropical Central Water exits toward the Atlantic Ocean. The mean value for the meridional (North-South) transport for a sampled year was –1.85 ± 0.25

sverdrup In oceanography, the sverdrup (symbol: Sv) is a non- SI metric unit of volumetric flow rate, with equal to . It is equivalent to the SI derived unit cubic hectometer per second (symbol: hm3/s or hm3⋅s−1): is equal to . It is used almost ...

(Sv) into the Caribbean Sea. The barotropic tide (surface tide) propagates from northeast to southwest along Mona Passage. The "principal lunar semi-diurnal" constituent, also known as the ''M2'' (or ''M''₂), accounts for 52.35% of the total variance observed in the ocean currents, and the semidiurnal current ellipses, with a clockwise rotation, are roughly aligned in a north-south direction. Semidiurnal tidal currents impinging on a submarine ridge known as ''El Pichincho'' can force the generation of an internal tide with a wave height of .

Underwater glider An underwater glider is a type of autonomous underwater vehicle (AUV) that employs variable-buoyancy propulsion instead of traditional propellers or Underwater thruster, thrusters. It employs variable buoyancy in a similar way to a profiling floa ...

observations reveal wave damping as the internal tide propagates south along the Mona Passage towards the open Caribbean Sea. Internal tides at ''El Pichincho'' can elevate the turbulent vertical diffusivity values (or eddy diffusion), and with a reduction of the

Richardson number The Richardson number (Ri) is named after Lewis Fry Richardson (1881–1953). It is the dimensionless number that expresses the ratio of the buoyancy term to the flow velocity, flow shear (fluid), shear term: : \mathrm = \frac = \frac \frac wh ...

at the base of the pycnocline. The development of Kelvin-Helmholtz instability during the breaking of the internal tide can explain the formation of high-diffusivity patches that generate a vertical flux of

nitrate Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...

(NO₃⁻) into the

photic zone The photic zone (or euphotic zone, epipelagic zone, or sunlight zone) is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological ...

and can sustain new production locally. Higher values of

primary productivity Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Works * ...

were observed near the wave trough, than those observed during periods of maximum solar irradiance at noon. Images from the Moderate-Resolution Imaging Spectroradiometer (MODIS) and

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

(ISS) photography show the sea-surface manifestation of packets of internal

solitons In mathematics and physics, a soliton is a nonlinear, self-reinforcing, localized wave packet that is , in that it preserves its shape while propagating freely, at constant velocity, and recovers it even after collisions with other such locali ...

(or nonlinear internal waves) generated at ''Banco Engaño'', located at the northwest margin of the Mona Passage. The packets propagate either into the Caribbean Sea or the Atlantic Ocean depending on the direction of the currents that forced their generation. Surface tides, internal tides, internal solitons, inertial currents, and the low-frequency water mass transport between the Atlantic Ocean and the Caribbean Sea make the Mona Passage a very dynamic environment.

References

External links

Ecology and Geology of the Mona Passage Region

Ocean Physics Education, Inc.

{{in lang, es Bodies of water of the Dominican Republic Bodies of water of Puerto Rico Dominican Republic–Puerto Rico border Geography of Hispaniola Geography of Puerto Rico Geography of the Dominican Republic International straits Straits of the Caribbean

Islands

Structure and seismicity

Physical oceanography

See also

References

External links