Sea Level Rise in the Mediterranean Sea and Mallorca Island - Essay Example

? Sea level rise in the Mediterranean Sea and Mallorca Island Introduction The sea levels have been in transition with the time from time immemorial. The changes in the sea levels refer to the rise and fall in the level of water in the sea. This level has been fluctuating with time rather than being constant. Perhaps the questions someone would like to ask here is, why is the sea level changing over time? On the other hand, emerging issues arise as to what are the causes of sea level change. The answers to these questions can be given in a twofold criteria and include the change in the estuarine geodatum caused as a result of the flow of melt water from the glaciated lands across the globe into the sea. Consequently, thermal expansion of the upper layers of the sea water caused by the decrease in water density due to its warming leading to the rise in the sea levels (Szabados, 2002). The occurrences of these situations within the earth’s geographical landscape usually lead to varied rise in the sea levels in some areas and a fall in certain areas. Another cause for the changes in the level of the seawater is the rising or uplifting of the lands close to the sea. This often causes the decline in sea levels in some regions though to a limited extent. Sea level rise is of recent times has resulted in very great concern to the global community as environmental conservation issues is a global phenomenon and is of global concern. According to the statistics taken by the Intergovernmental Panel on Climate Change (IPCC) using the satellite images, the global sea levels have been rising tenderly at an average rate of about 3mm per year from 1993 to 2007 (IPCC, 2007). This report highlights the various effects of the continued rise in sea level within the global context. This report will also look at the changes in the sea level in the Mallorca and the Mediterranean regions of the world, their causes and consequences on the adjacent lands as well as the extent of the influences on the coastal communities around the mentioned areas. Mallorca is a small island in the Mediterranean Sea off the coast of Spain that has been characterized by a number of notable cases of sea level change. Studies by Jeffrey Dorale shows that the sea level was about one meter above the levels that reached 81000 years ago indicating a positive deviation in the in the level of the sea waters. The rise in the levels as he argues is brought about by the rapid melting of ice around the globe. The ice water consequently finds its way into the sea thereby raising the water levels by about one meter for every fifty years (Jieffrey, 2010). The observable results of this rise in the levels of the Mediterranean Sea are seen as a spillover effect in the communities surrounding the sea. Most of the communities that were once living closer to the sea have retreated by about sixty miles away from the coastline as much of the land has been submerged under the seawaters. Moreover, Barnetti (2005) argues that the formally dry lands adjacent to the Mediterranean regions have now been covered under water thereby continuously diminishing the amount of cultivatable lands in these regions and the consequent migration of people out of these areas (Barnetti, 2005). Geography has evolved as a more organized subject of study that uses different methodological approaches in understanding various observed geographical phenomena. On one hand, physical geography adopts a scientific and rational approach while on the other hand human geography relies heavily on descriptive techniques in examining the relationship between complex human factors and their influence on geographical environment. The scientific approach has been adopted widely in the study of physical geography based on observation, precise scientific experience and sound precision and measurements of the geographical phenomena. As such, the Mediterranean region has been experiencing constant shifts in its climatic characteristics contributed mostly by the wide variation in the social- economic and the environmental factors in operation around the region stemming from the morphology of the Mediterranean region and the atmospheric components that give the region its desired climatic characteristics. The population variability and density in these regions are therefore the major contributing factors for the rapid change in the Mediterranean climate. Most human activities being carried out in these areas are deemed detrimental to the environment. The population density, which is high in this region, has concentrated on the exploitation of both the underground and surface waters leading to their exhaustion. The variations in the cultural practices therefore form the major part of the influences to the rapid climate change in the area (Flint, 2003). The evidences of sea level rise in these regions are signified by the numerous submerged caves around the coasts of the Mallorca Island off the coast of Spain. Various caves have been submerged under the seawaters that were formerly above the surface indicating the rise in the sea levels. A spectacular evidence for the rise has also been noted by the scientists studying the oceanographic composition of these areas is the submergence of the beaches that were very dry some years ago (Fortun, 1990). Similar studies also suggest that the Mediterranean sea levels are on the rise at an alarming rate and will still continue rising within the time span of 50years. These rises in sea levels have been more related to the increased atmospheric temperatures that are likely to be experienced within the same period under study. Geography, the Mediterranean Sea has been outlined to have a connection to the Antlantic Ocean and the Black Sea. The sea has with its numerous islands including Crete, Rhodes and Lesbos among other islands that essentially place the Sea as an important geographical feature. Further, the usual daily weather experienced in the Mediterranean ranges from a hot and mild summer regimes and progressively rainy winters. The table below shows the trends in the change in the sea level over time Estimates of the global sea level change Value (>0.5?) Cryologic estimates Source 11 Many stations, 1807- 1939 Van der Veen (1997) 12- 4 ? Combined Methods Trupin (1990) 11± 0.4? six stations 1807-1943 Robin (1996) 12? Selected Stations 1900-1950 Reeh (2005) 30? Many stations 1935-1975 Zwally (2009) 12? Many stations1880-1980 Board (2004) 15? Many stations 1900-1975 Trupin (1990) 15± 0.15? selected stations 1903-1969 Robin (1996) 14± 0.14? Many stations 188-1980 Niewman (2006) 23± 0.23? Many stations 1930-1980 Zwally (2009) 12± 0.3? 130 stations 1880- 1982 Robin (1996) 10± 0.1? 130 stations 1880- 1982 Reeh (2005) 11.5? 155 stations 1880- 1986 Van der Veen (1997) 24± 0.9? 40 stations 1920- 1970 Niewman (2006) 17± 0.13 ? 84 stations 1900 1980 Zwall ( 2009) ?= value plus 95% confidence interval Causes of the sea level change in the Mediterranean Sea Several factors are in action in contributing to the changes in the sea level on the Mediterranean Sea as has been noted by oceanographers in the recent past. These studies further reported that since 1943, the water levels in the Mediterranean Sea have risen at the rate of about 1.5 meters per year. These movements have since then been identified as, vertical land movements resulting from the various isostatic adjustments or movements such as the tectonic processes, the process of sedimentation, and anthropogenic activities carried out by the people living around the region. Largely, these activities include the extraction of oil and ground water for both domestic and commercial purposes. Further, the atmospheric factors such as the variations in the atmospheric pressure of the region, the effects of the winds passing over the region, the ocean currents and the density in the seawater have been identified as contributing factors. All these factors are in operation in the process of the modification of the region’s climate contributing into the noted changes in the water levels in the Mediterranean Sea. Human/anthropogenic factors The intensive human activities carried out in the Mediterranean region have been of great concern to the scientific community as far as the rising levels of the Mediterranean Sea are concerned. Given the hot and humid climatic conditions in the area, human activities in the region have contributed into the modification of the regional climate. These include the mining process and its associated impacts on the environment. The Mediterranean region is characterized by the major oil producing countries in the world. Oil production from these regions has contributed into the immense pollution of the surrounding environments. The gases produced from the oil mining countries are known to have the ability to cut across the global boundaries therefore affecting the global atmosphere (Eckman, 2008). The process of atmospheric pollution is a global phenomenon. The most industrialized countries have the highest injection of the greenhouse gases into the atmosphere and as such are the greatest contributors to atmospheric modification. Among the major detrimental industries that contribute much to the deposition of the greenhouse gases in the global atmospheres are the oil extraction and processing industries. A significant proportion of these industries are present in the countries that border the Mediterranean Sea to the African side and the more industrialized countries on the European side, which inject their industrial gases into the atmosphere increasing the global temperatures, a process, called global warming (Haeberti, 2009). The effects of global warming cause the melting of polar ice which finds its way into the sea via the major oceans, the diagrams A and B below shows the variation in the mass balance of the global glacier over time with an increase in temperature. NOTE: The figure shows the dependence of ablation (evaporation and surface run offs) against accumulation on the annual surface temperature (the upper panel). The diagram is not static and changes from one place to another depending on the accumulation of GHGs in the atmosphere of the place. From the diagram above, it is evidence that the rate of global glacier depletion increases with an increase in the global temperatures because of the global increases in temperatures, the glacier in Greenland, Antarctica and those existing in small amounts in the tropical regions. The melt water then finds its way into the sea thereby increasing the global sea levels. However, the increases may not be significant on large ocean bodies but on the small seas like the Mediterranean Sea, the effects are clearly evidenced, as the submergence of the shorelines is conspicuous. Oil and ground water exploitation This is the main contributory factor to the slow changes in the rising levels of the waters in the Mediterranean Sea. As the ground water and oil is exploited in the regions surrounding the sea, voids and cavities are left in the grounds that were formally occupied by the ground water or oil (Bindschadler, 2001). Gravitational pull on the earth’s surface then leads to the voids being filled up by the seawater infiltrating from the seabed into the ground where they join these waters. These processes always act as a counter effect to the rise by trying to keep the water levels somehow stable. However, the rates of polar ice melts in comparison to that of the underground seepage in the region are out of balance as more water gets into the sea from the polar ice lands. Even though the rates of water seepage from the sea helps in replacing the underground water banks in these areas, the extent of depletion of the underground waters by the communities living around the Mediterranean region is high leading to the insufficiency in the surface waters for plants' growth. Farming practices around the Mediterranean Sea communities The other anthropogenic factors that have equally contributed to the rise in the sea levels around the Mediterranean region include to a lesser extent the poor farming methods practiced by the people around the region. These include overstocking due to pastoralism especially on the African continent where the moving caravans are a common phenomenon along the margins of the sea. These animals indirectly interfere with the surrounding environment by destroying vegetation in the area, because of this; the accumulation of the greenhouse gases in these areas significantly increases since trees act as carbon IV oxide absorbers (IPCC, 2007). The resulting effects of this are transmitted to the global spheres where the global increases in temperatures leads to the melting of the ice in the glaciated lands resulting into the rise in the sea levels. Evidences of the rise in the sea levels along the Mediterranean coasts have been observed on the coasts of Mallorca as shown in the diagram below. From the diagram, new phases of erosion have started forming as the coastal shoreline is submerged under the sea. The new phase in cliff erosion, cliff evolution is usually an indicator for the increase in the sea levels. This then is used an indicator to justify the rise in sea level because of changes in the various practices largely poor agricultural and farming practices. A research carried out by Dorale and his colleagues on the levels of sea rise in the Mallorca island indicates a positive results for the same. Dorale noticed that the sea levels were higher around 81000 years ago than they are today according to the findings in the Mallorca Island. The research was carried out on cave deposits on the coastal banks of the small island off the Mediterranean coasts within the caves found on it. The team of researchers led by Dorale et al (2010) found out that the markings of encrustation (a kind of mineral deposition in caves because of the mixing of the seawaters with the fresh inland waters) were in varied heights indicating a continuous fluctuation trend in the levels of seawaters. Thus, they did mark on several other speleothems such as the stalagmite, stalactites and pillars indicated the same results from over 81000 years ago. For that they concluded, “Large fluctuations in global sea level occurred throughout the last interglacial/glacial cycle, but the precise magnitudes of some of these fluctuations are subjects of energetic debate”. Further arguing that “Along the coast of Mallorca in the western Mediterranean, caves exist that provide an extraordinary setting for capturing past sea-level changes….throughout the Middle and Late Quaternary, the caves were repeatedly flooded by glacioeustatic sea-level oscillations. The water level of each flooding event was recorded by a distinct encrustation of calcite or aragonite over existing speleothems and a long cave wall” (Dorale et al, 2010). According to Dorale at al (2010) these fluctuations were as a result of the interglacial periods which often resulted into the glacial melts and the consequent rise in the levels of the sea waters. The aspect of sea level rise can therefore be attributed to the periodic polar glacial melts evidenced by the encrustation markings on the speleothems within the caves of the Mallorca Island. Effects of isostacy and tectonic movements on the vertical movement of lands along the Mediterranean coasts The coastline along the Mediterranean Sea has been a stable region for a long time as far as the effects of the tectonic forces are concerned. These areas have been shielded from seismic forces for over 2000 years. The stability has been marked by the stable shoreline/ coastal features (geomorphologic features) as well as the occurrence of certain species of flora and fauna along the Mallorca coast. These have however been interfered with in the recent past due to the occurrence of an uplift along the Mediterranean coasts as suggested to have been influenced by the tectonic uplifts in the late quaternary times. The sea levels along the Mallorca coasts just like in the rest of the Mediterranean region has been undergoing the process of uplifting with time due to the high level of glacial offloading in the high latitude glacial sheets as well as the loading of the ocean floor with melted water (Board, 2004). As the polar ice melts, the melt water finds its way into the sea thereby increasing the amount of load over the sea surface. This results into the reciprocate uplift on the adjacent lands close to the sea. Arising from this, Kurt (1998) argues that this is what has prevented the coastal landmasses along the Mediterranean coastline from submergence and as a result, only minor cases of submergence are evidenced in the regions i.e. along the coasts of Mallorca as well as that of the Mediterranean region along the African and European coasts. The diagram bellow shows the raising of the lands adjacent to the sea in off the coast of Mallorca. Conclusion In conclusion, the Mediterranean Sea has been undergoing a period of surges in the levels of water in the sea with time right from the late Pleistocene period into the recent times. This has been contributed by the melting of the polar ice in the high latitude regions of the world such as in Greenland and the Antarctic regions. Further, the mid latitude ice caps i.e. those found on the top of high mountains in the mid latitude regions which later on finding their ways into the sea leading to the swelling of the sea waters and the consequent submergence of the adjacent coastal lands. Alongside these effects are the human or anthropogenic factors that indirectly lead to the changes in the global temperatures, which in turn affect the stability of the polar glacier. Tectonic motions and isostatic balances on the other hand counteracts these effects by raising the adjacent landmasses contrary to their submergence preventing total submergence. References Barnetti, T. P. (2005). Long term climate change in observed physical properties of the oceans. Geophysics , 91- 107. Bindschadler. (2001). Minerals and mineralogy. Effects of mining on the sea level , 125- 131. Board, P. R. (2004). Glaciers, Ice sheets and the Sea Level. Effects of Carbon iv Oxide on climate Change , 24 (12), 215- 217. Dorale, J. 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