Alternative Causes for Sea Level Change, Gulf of Mexico
Sea level has been rising at an accelerating rate along the U.S. East Coast and Gulf of Mexico as an effect of numerous causes. This is according to UCSUSA (1), that asserts that the major cause of these changes is global warming. From the geological records, natural climatic factors have affected the levels of the sea in the Gulf of Mexico (UCSUSA, 1). The level has been varying between 6-8 mm with greater rises having been experienced in the geophysical and oceanographic forces (UCSUSA, 2). The global average sea level is approximated to have risen by eight inches from 1880-2009, which translates to about 70% above the 20th century average. One major factor for the change along the Gulf of Mexico is global warming due to human activities like burning of coal and cutting down of forests. Increased human settlement in the region is also a factor that has led to the changes in the sea. These activities have resulted to increased atmospheric concentrations of heat trapping gases that have caused the planet to warm by 1.40C since 1880. Increasing temperatures on the ocean waters, thereby results to thermal expansion as another major cause of increased sea level for the last 75 years, which shrinks glaciers, ice caps, and ice sheets at a faster rate due to increased temperatures thereby adding to ocean’s waters.
Thermal expansion along the sea and loss of ice has adversely driven the average sea level rise to more than eight inches from 1880 (Science Connections, para. 1). Glaciers, ice caps, and sheets presently account for more than 52% of the sea level rise while groundwater withdrawal contributes for 10% of the change within the Mexican coast. Long term and short-term variations such as wave tides, specific flood events such as those related to winter snow melt of coastal storm contribute to changes in sea level (Union of Concerned Scientists1, 4). Long-term variations are caused by repeatable cycles such as seasonal weather patterns, earth’s declination, coastal and ocean circulation, anthropogenic influences like dredging, vertical land motion, and the southern oscillation. Previous studies state that for the last 20 years, summer peaks have been increasing while winter troughs have been getting lower, which can potentially increase hurricanes and stress delicate ecosystems (Union of Concerned Scientists2, 2). Within the Gulf regions, land has been subsiding, which results to the ocean penetrating farther inland. Moreover, global warming emissions are projected to contribute heavily to the sea level changes since the damage has already taken place.
The Gulf of Mexico is presently experiencing more floods than previously due to increased tidal movements. According to Union of Concerned Scientists2 (3), there is usually a combined gravitational pull of the sun and the moon, which results to tides that rise above the normal height, twice every month, during the new and full moons. The fact that the region is also a residence to water species and habitats affects the sea level due to the expected benefits to the ecosystems. Climate changes have besides been known to affect coastal areas with the variation of frequency and intensity of storms, increased precipitation, and temperatures (According to Union of Concerned Scientists1 2). Rising concentrations of carbon dioxide in the atmosphere is also a cause of the variation of the sea level changes since it causes the ocean to absorb more gases thereby becoming more acidic. This acidity thereby results to significant effects on coastal and marine ecosystems. Heavier rainfall will increase the levels. Land movement, which results to changes in the sea a consequence of land movement, is up and down. In the event that land is sinking, the relative sea level rises more than the global level. Sea level, a factor defining the coastal levels is a human and urban hazard due to its prevailing variation.
UCSUSA. Infographics. 2016.
Union of Concerned Scientists. Encroaching Tides. (2014). Retrieved in 2016 from
Union of Concerned Scientists. Causes of Sea Level Rise: What the Science Tells us (2013).