Sea Level ChangeSea Level Change

By:By:

Amanda Bura &Amanda Bura &

Amy CrossAmy Cross

What is Sea Level Change?What is Sea Level Change?

• The rise and fall of the sea level due The rise and fall of the sea level due to multiple complex factors such as to multiple complex factors such as plate tectonics, glaciers, thermal plate tectonics, glaciers, thermal expansion and global warming.expansion and global warming.

• It is difficult to measureIt is difficult to measure

• Has been derived mainly from tide-Has been derived mainly from tide-gauge datagauge data

Why Does It Occur?Why Does It Occur?

• Concurrent rise in global Concurrent rise in global temperature over past 100 years.temperature over past 100 years.

• Thermal expansions of oceans Thermal expansions of oceans accounts for about 2-7 centimeters accounts for about 2-7 centimeters of the sea level rise.of the sea level rise.

• Retreat of glaciers and ice caps Retreat of glaciers and ice caps accounts for about 2-5 centimetersaccounts for about 2-5 centimeters

Sea level Sea level rise due to rise due to

certain certain trends in the trends in the environmentenvironment

• Measurements Measurements suggest that suggest that sea level has sea level has risen worldwide risen worldwide 15-20 cm. in 15-20 cm. in the last the last century.century.

• Along the U.S. Along the U.S. coast sea level coast sea level has been rising has been rising 2.5-3 mm. a 2.5-3 mm. a year.year.

Unusual Rise in Sea LevelsUnusual Rise in Sea Levels

• Bangladesh Bangladesh is is experiencing experiencing high and high and unusual unusual changes of changes of sea levels sea levels due to due to subsided subsided river delts.river delts.

Effects of Sea Level ChangeEffects of Sea Level Change

• On small time scales continents can On small time scales continents can be joined or separated by changes in be joined or separated by changes in sea level.sea level.

• Relatively small changes in sea level Relatively small changes in sea level can have a major effect on the can have a major effect on the geography of a continent. geography of a continent.

Effects for the FutureEffects for the Future

• Sea level could rise 40 to 65 cm by the year Sea level could rise 40 to 65 cm by the year 2100, due to predicted 2100, due to predicted  greenhouse-gas-induced climate warming.  greenhouse-gas-induced climate warming.

• It is important to study records of how sea level It is important to study records of how sea level

has been changing.has been changing.

• Climatologist Kevin Trenberth notes that Climatologist Kevin Trenberth notes that while predictions for sea level have while predictions for sea level have changed over the years, rising seas changed over the years, rising seas remain "a major problem on long-time remain "a major problem on long-time scales.... Even if you stabilize scales.... Even if you stabilize temperature and greenhouse gases, sea temperature and greenhouse gases, sea level will continue to rise."level will continue to rise."

ReferencesReferences

• http://www.csr.utexas.edu/gmsl/main.htmlhttp://www.csr.utexas.edu/gmsl/main.html

• http://www.discoverourearth.org/student/sea_level/index.htmlhttp://www.discoverourearth.org/student/sea_level/index.html

• http://www.grida.no/climate/vital/19.htmhttp://www.grida.no/climate/vital/19.htm

• http://www.usna.edu/NAOE/courses/en420/bonnette/http://www.usna.edu/NAOE/courses/en420/bonnette/Sea_level_rise_and_tides.htmlSea_level_rise_and_tides.html

• http://yosemite.epa.gov/oar/globalwarming.nsf/content/http://yosemite.epa.gov/oar/globalwarming.nsf/content/ClimateTrendsSeaLevel.htmlClimateTrendsSeaLevel.html