Our Home: The Gulf of Mexico.

 

The Gulf of Mexico located in the subtropical zone, is a semi enclosed sea basin that communicates with the Caribbean Sea and the Atlantic Ocean through the channel of Yucatan and the Straits of Florida, respectively. Altogether, it has 1.6 million of km2 of surface and an approximate volume of 2,3 million of km3. It has a length of 1600 km in the East-West line, 1300 km in the line North-South in its western portion and 900 km in the Eastern and Orient.

gulf of mexico

A little bit of history about the Gulf of Mexico.
The Gulf of Mexico’s first exploration came 8 years after Christopher Columbus arrived in America when Juan de la Costa utilized information from several voyages to create the first map of this semi enclosed sea.  In those years, Spanish gave a variety of names by the cartographers of Sevilla: “Golfo de Florida”, “Golfo de Cortes”, “Sinus Magnus Antillarum” (in reference to Antilles), and even “Mare Cathaynum” (Chinese Sea).  Subsequently the Spanish used the practical name ‘Mediterraneo de America”, finally, in 1550, they clearly labeled it as “El Golfo de Mexico” (The Gulf of Mexico in spanish).

After Spanish colonization in America, France, England and Holland established the territory that currently forms the Gulf of Mexico as well as the Antillean Islands during the seventeen century. Later during the European crisis of the nineteen century, with great political and economic vision, the USA acquired Louisiana from France in 1803 and Florida from Spain in 1819. In 1823, Mexico concluded its Independence, and in 1836 Texas became a part of the USA, then in 1902, Cuba reached its independence, thus forming the Gulf of Mexico as it is at the present time.

Characteristics of the Gulf of Mexico:

In order to relate globally the Gulf of Mexico it is important consider that is ninth in area, fifth in average depth and ninth in volume among oceans and semi enclosed seas. [Turner, 1999]

 

Área (km2)

Average depth (m)        

Volume (1,000 km3)

Pacific Ocean

166,242,517

3,940

654,921

Atlantic Ocean

86,557,800

3,575

309,471

Indian Ocean

73,427,795

3,840

281,954

Arctic Ocean

13,223,763

1,039

13,740

South China Sea

2,974,615

1,464

4,354

Caribbean Sea

2,515,926

2,575

6,478

Mediterranean Sea

2,509,969

1,501

3,769

Bering Sea

2,261,070

1,491

3,372

Gulf of México

1.507.639

1.615

2.434

Sea of Okhotsk

1,392,125

973

1,354

Sea of Japan

1,012,949

1,667

1,688

Hudson Bay

730,121

93

68

East China Sea

664,594

189

126

Andaman Sea

564,879

1,026

580

Black Sea

507,899

1,191

605

Red Sea

452,991

538

244

North Sea

427,091

94

40

Baltic Sea

382,025

55

21

Yellow Sea

293,965

37

11

Persian Gulf

229,992

99

23

Gulf of  California

153,069

724

111

Table 2. Area, average depth, and volume of the larges oceans and enclosed water bodies (from Turner, 1999)

Despite the restricted inflow, a major current, the Loop Current, flows through the Gulf transporting approximately 25 x 10^6m^3/sec of water and occasionally meandering and shedding eddies. [Shiller, 1999]

The river basin drainage of the Gulf is very big, and has a greater surface area of 5.180.000 km2 than it includes five countries:  Mexico, the United States, Guatemala, Cuba and Canada.  The greater extensions of this river basin correspond to USA and Mexico.   The former drains into the Missouri-Mississippi River system and the latter into the Grijalva-Usumacinta system. About two-thirds of the area of the continental USA drains into the gulf, as does about half of the area of Mexico [Zarate, 1999; Martinez, 1998, Day et al. 2003]

map

Figure 4 Main river systems of the Gulf of Mexico drainage.
(from García 1972)

Coastal barrier landforms inshore of the Gulf of Mexico consist of islands, coastal lagoons, and beaches that extend in an irregular arch from Florida to Yucatan. Sea level rise since the last glacial period ended approximately 10,000 years ago has greatly affected the coastal landforms seen in the Gulf today. Present barrier landforms are relatively young, having been formed between 5000 and 6000 years ago when the main continental ice sheets melted and sea level rise began to stabilize. [USDI, 2000]

The coastal lagoons, rivers and estuaries constitute a hydrologic product of the encounter of two types of water and represent the best index of the quality of the river basin of the gulf [Castaneda and Contreras, 2003]. The Subtropical Water Sub superficial of the Caribbean (SWSC) with high content of salt and heat, enters the Gulf through the Channel of Yucatan and it moves in a clock wise sense (anti-cyclonal), being observed a current in a bow form (Loop Current) until the Straits of Florida (figure 5).

Besides the mass of water that comes from the different regions at the Atlantic Ocean, the 18 °C water from the North Atlantic, the Subtropical Water of the South from the South Atlantic and Intermediate the Antarctica Water from the Antarctic ocean, is a region with great amount of heat and salinity; [Cooper, 1990]

 

Figure 5. Loop Current in the Gulf of Mexico and general circulation of the currents in the Atlantic Ocean in the Caribbean (from Murphy and Hurlburt, 1999).

The Gulf has a very variable bathymetry (figure 6):  the Channel of Yucatan in its western part has a narrow continental platform of 2 km whereas to the north of the Yucatan Peninsula displays a wide one of 250 km. The Bank of Logwood, defined from the Eastern part of the Lagoon of Terminos to Mujeres Island, is very extensive and has a bottom with a very smooth slope, the slope is pronounced and approximately it uniforms excepting in the zone of the Cañón de Campeche.  The platform in Veracruz and Tamaulipas front is very narrow, and it expanded in front of Texas-Louisiana continuing until Florida.  In the center of the Gulf the depth is near the 3.600 m. [AMC, 1999; Cooper, 1990]

gulf of mexico2

 

Figure 6. Gulf of Mexico Bathymetry (from: Zavala-Hidalgo, et al., 2003)

Like the temperature, the distribution of the salinity strongly is related to the Loop Current, which has salinity greater to 36.8 above of the 200m, which is a result of the predominance of evaporation and precipitation in the region of the Caribbean. The salinity also depends on the season of the year. [De la Lanza-Espino, 2001, Caso-Chávez et al 2004]

 

Figure 7. Currents and temperatures distributed in the Gulf of Mexico (from Lugo-Fernandez and Hamilton, 2001)

Carbonate areas of the Florida Peninsula of the eastern Gulf and Campeche  region of the southern Gulf are characterized by steep margins and slopes that display the effects of mass movement processes on a variety of scales. [Walker et al., 2002]

The beaches and dunes are the most important atmospheres of sedimentation in the world, In these places where there is greater sediment accumulation (Grain of sand of different sizes) due to sea currents and winds have been transported by.  Both are considered extremely dynamic ecosystems that cushion the interactions between three great systems:  the sea, the Earth and the atmosphere. The profile of the beach represents the dynamic balance between the sediment transport towards the sea (erosion), the Earth (sedimentation) and throughout the coasts (current of drift). [Carranza-Edwards et al. 2004, Moreno-Casasola, 2004]

The wetlands of fresh water are related intimately to the set of estuarine and marine systems of the Gulf of Mexico.  Only in the Gulf of Mexico two of the most extensive flood plains in the continent exist, represented by the deltas of the Mississippi and the Grijalva-Usumacinta [Day et al. 2003, Lot, 2004]. Moreno-Cassasola [1998] proposes a regional subdivision of the wetland for the Gulf of Mexico as follows: 1. Delta of Mississippi, 2. Everglades,3. Central part of the Gulf of Mexico, 4. Delta of Usumacinta, 5. Peninsula Yucatan, 6.  Cuba

The emergent coralline reefs that only exist in the interior of the Gulf of Mexico it is founded on the Mexican continental platform; its degree of development is considerably elevated, analogous to the one of reefs of the same type in the Caribbean Sea.  These reefs systems are located mainly in two regions of the platform:  in Campeche and on front of the platform of Veracruz. However the Louisiana and Texas Artificial Reef Programs are the largest rigs-to-reef programs in the world. The program involves donating obsolete oil and gas structures for use as artificial reefs in lieu of on-shore removal. [Kaiser and Pulsipehr, 2005]