The precise nature and the reason for the formation of the Gulf of Mexico’s annual dead zone.
Answer to Problem 1CR
The annual dead zone of the Gulf of Mexico contains a large volume of water with low dissolved oxygen content and cannot sustain animal marine life. The annual dead zone forms due to the depletion of most of the dissolved oxygen in the Gulf’s bottom layer of water.
Explanation of Solution
The Gulf of Mexico’s annual dead zone contains a massive volume of water with low dissolved oxygen content (below 2 parts per million). This condition is responsible for little or no animal marine life in the dead zone. The low dissolved-oxygen levels suffocate bottom-dwelling-fish, crabs, oysters, and shrimps and drive away faster-swimming marine animals.
During spring and summer, large quantities of crop fertilizers (mostly nitrates and phosphates) flow into the Mississippi River and get collected in the northern Gulf of Mexico. This excess of plant nutrients results in the explosive growth of phytoplankton that eventually dies and sinks in the bottom of the water. The dead organisms get decomposed by oxygen-consuming bacteria and cause depletion of most of the dissolved oxygen in the Gulf’s bottom. The resulting volume of water containing low dissolved-oxygen content is termed as a dead zone.
Want to see more full solutions like this?
Chapter 11 Solutions
Environmental Science (MindTap Course List)
- 47) Deflation is the process by which A) wind transports smaller particles leaving behind only larger pebbles and rocks. B) sands are deposited closer to the source area and silts are deposited farther. C) sand dunes migrate downwind as sand saltates up the windward face. D) rocks are worn away by bombardment of particles carried in Windstream.arrow_forward46) In Barchan dunes, the slip face is oriented A) on the convex side of the dunes. B) parallel to wind direction. C) on the concave side of the dunes. D) at varying angles.arrow_forward43) Glacial abrasion is when A) boulders are fragmented into smaller particles under the weight of the overlying ice. B) blocks of rocks are plucked from the underlying bedrock. C) rocks are carried at the base of a glacier and grind away at the underlying bedrock. D) debris fall onto the top of the glacier and are carried down glacier.arrow_forward
- 34) Which of the following is true of soils? A) Soils rich in mineral matter are usually dark in colour. B) They usually require hours or days to form. C) Their development is affected by climate and organisms. D) Their properties are not affected by the type of rock from which they form. E) Older soils usually have fewer horizons than younger soils.arrow_forward44) In periglacial environments, the layer of ground that thaws every summer and freezes every winter is called A) frost layer B) permafrost C) active layer D) discontinuous permafrostarrow_forward42) The ablation zone of a glacier A) has a total positive mass balance. B) is where snow accumulates and transforms into ice. C) is located in the upper part of the glacier. D) is where ice mass is lost.arrow_forward
- 41) Alpine glaciers A) are the largest types of glaciers. B) conform to the shape of the landscape. C) cover large sections of continents. D) show no relationship with the underlying topography.arrow_forward40) Marine terraces are the result of A) coastal emergence through uplift or sea level decrease. B) coastal submergence through erosion or sea level increase. C) deposition of sands by the longshore current. D) wave refraction causing a loss of energy that allow sediments to be deposited.arrow_forward39) Translatory waves A) are the types of waves located furthest away from the shore. B) are slowed down by friction with the bottom of the ocean. C) move water particles in perfectly circular orbits. D) do not interact with the bottom of the ocean.arrow_forward
- 37) Which of the following terms is used for a type of sediment transport in streams? A) discharge. B) overland flow. C) saltation. D) sheet flow. E) abrasion.arrow_forward33) You would expect only slight physical and chemical weathering under conditions of A) temperatures below freezing. B) extreme cold and high precipitation. C) extreme heat and no precipitation. D) lower mean annual rainfall and temperatures. E) higher temperatures and lower precipitation.arrow_forward36) Soil moisture that plants are capable of accessing and using is called A) hygroscopic water. B) wilting point water. C) gravitational water. D) free molecular water. E) capillary water.arrow_forward
- Applications and Investigations in Earth Science ...Earth ScienceISBN:9780134746241Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. TasaPublisher:PEARSONExercises for Weather & Climate (9th Edition)Earth ScienceISBN:9780134041360Author:Greg CarbonePublisher:PEARSONEnvironmental ScienceEarth ScienceISBN:9781260153125Author:William P Cunningham Prof., Mary Ann Cunningham ProfessorPublisher:McGraw-Hill Education
- Earth Science (15th Edition)Earth ScienceISBN:9780134543536Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. TasaPublisher:PEARSONEnvironmental Science (MindTap Course List)Earth ScienceISBN:9781337569613Author:G. Tyler Miller, Scott SpoolmanPublisher:Cengage LearningPhysical GeologyEarth ScienceISBN:9781259916823Author:Plummer, Charles C., CARLSON, Diane H., Hammersley, LisaPublisher:Mcgraw-hill Education,