Lecture 12: Sea Level Rise

• Warm water is less dense than cold water
• As water warms

  It expands and takes up more room
• Thermal expansion


  As water gets hotter, it expands, similar to how steam expands when heated, causing the sea level to rise
• Thermal expansion causes the sea level to rise as the ocean warms up
• Melting of continental glaciers

  Warmer temperatures cause ice in glaciers to melt, and the water runs into the ocean, leading to a decrease in the size of glaciers and more water entering the ocean
• Scientists track the worldwide melting of glaciers and the water entering the ocean
• Greenland and Antarctic melting contribute significantly to sea level rise
• Greenland and Antarctica have enormous ice sheets that are melting due to global warming
• Feedback loops exacerbate the melting of ice in Greenland and Antarctica
• Greenland melting affects the water in the North Atlantic, making it fresher
• There has been a significant loss of ice in Greenland and Antarctica over the last 16 years
• Ice loss is measured in meters per year
• Ice loss contributes to rising sea levels
• Sea level rise in Chesapeake Bay is particularly bad
• Chesapeake Bay is sinking as sea level rises


  Due to glacial rebound phenomenon
• Glacial rebound


  Land that was covered by glaciers sank down, while areas without glaciers rose up
• Maryland and places south of it are sinking due to glacial rebound
• Places like New York and most of Canada are rising due to glacial rebound
• Land in Maryland is sinking as sea levels rise, leading to the loss of islands in Chesapeake Bay
• Approximately 400 different islands have been lost in the Chesapeake Bay due to erosion and land sinking
• Islands affected by sea level rise

  • Holland Island
  • Tangier Island
• Holland Island had houses, farms, and other structures, but due to sea level rise, it eroded and eventually collapsed into the bay
• Tangier Island has lost a significant amount of land over time and may disappear in our lifetimes
• As sea level increases

  Salt water from the ocean moves farther up rivers, bays, and estuaries
• Negative effects of saltwater intrusion

  • Corrosion of infrastructure like bridges and sewage pipes
  • Intrusion into groundwater affecting wells
• Saltwater intrusion is the movement of saltwater into groundwater near the coast, causing corrosion of infrastructure and contamination of wells
• Florida, particularly areas like Fort Lauderdale and Miami, are struggling with saltwater intrusion due to their permeable land
• Sea level rise leads to saltwater intrusion, which can contaminate wells used for drinking water, agriculture, and industry
• NOAA has developed a tool to visualize how sea level rise will affect coastal areas in the US
• Sea level rise has various effects on oceans due to climate change