Oceans And Seas Questions Long
Sea level rise is primarily caused by two major factors: thermal expansion of seawater and the melting of land-based ice.
1. Thermal Expansion: As the Earth's atmosphere warms due to the increase in greenhouse gases, such as carbon dioxide, the oceans also absorb heat. This causes the seawater to expand and take up more space, leading to a rise in sea levels. Thermal expansion is estimated to contribute about half of the current sea level rise.
2. Melting of Land-Based Ice: The melting of glaciers, ice caps, and ice sheets on land is another significant factor contributing to sea level rise. As global temperatures increase, these ice formations melt and discharge water into the oceans. The melting of ice in Greenland and Antarctica, in particular, has a substantial impact on sea level rise. This process is accelerated by the warming ocean waters that come into contact with the ice shelves, causing them to melt from below.
Other factors that contribute to sea level rise include:
3. Loss of Ice Mass: Besides melting, ice loss can also occur through calving, where chunks of ice break off from glaciers or ice shelves and enter the ocean. This process adds to the overall volume of water in the oceans, contributing to sea level rise.
4. Changes in Land Water Storage: Human activities, such as the extraction of groundwater and the construction of dams, can alter the distribution of water on land. When water is removed from underground aquifers or stored in reservoirs, it eventually makes its way back to the oceans, leading to a rise in sea levels.
5. Ocean Currents and Circulation Patterns: Changes in ocean currents and circulation patterns can also influence sea level rise regionally. For example, when warm ocean currents are redirected towards coastal areas, they can cause higher sea levels in those regions.
It is important to note that sea level rise is a complex phenomenon influenced by various natural and human-induced factors. The rate of sea level rise is expected to accelerate in the coming decades due to ongoing global warming and the continued melting of land-based ice. This poses significant challenges for coastal communities, ecosystems, and infrastructure worldwide.