Sea Level Rise

What is the primary contributing factor to the global mean sea level rise since 1880?

• Expansion of underwater volcanoes

• Meltwater from glaciers and ice sheets

• Decrease in ocean salinity

• Reduction in atmospheric pressure

How does the average rate of global mean sea level rise from 2006–2015 compare to most of the twentieth century?

• It remained constant

• It decreased

• It increased by 2.5 times the average rate

• It doubled

• It increased at the rate of 1.4 mm/year

What are some local factors that can cause variations in sea level rise at specific locations?

• Solar radiation and lunar cycles

• Atmospheric pressure and wind patterns

• Ground settling, erosion, upstream flood control, land rebounding and regional ocean currents

• Changes in ocean salinity and underwater topography

In which U.S. regions are the fastest rates of sea level rise currently observed?

• Pacific Northwest and Alaska

• Gulf of Mexico and mid-Atlantic

• Northeast and Midwest

• Great Plains and Rocky Mountains

Why is sea level rise a significant concern for urban settings along coastlines?

• It causes earthquakes and tsunamis

• It leads to an increase in freshwater aquifers

• It threatens infrastructure, including roads, bridges, and power plants

• It benefits coastal ecosystems by providing additional habitat for fish and wildlife

What are the two main contributors to global mean sea level rise due to global warming?

• Expansion of ocean floor and changes in atmospheric pressure

• Melting of glaciers and ice sheets + thermal expansion of ocean water

• Changes in ocean currents and variations in underwater topography

• Shifts in tectonic plates and the decline of liquid water on land.

How has the contribution to sea level rise from melting ice and heat expansion changed over the past few decades?

• The contribution from melting ice has decreased, while heat expansion has remained constant.

• Both melting ice and heat expansion have contributed equally throughout the recent decades.

• The contribution from melting ice has increased significantly, surpassing heat expansion.

• The contribution from heat expansion has increased, surpassing melting ice.

How did the ice loss from the Greenland Ice Sheet change from 1992-2001 to 2012-2016?

• It decreased

• It remained constant

• It doubled

• It increased seven-fold

What is the primary method for measuring sea level since the early 1990s?

• Measurement of daily high and low tides; tide gauges

• Analysis of underwater topography

• Use of manual and automatic sensors

• Satellite altimeters using radar pulses

How do satellite altimeters measure sea level from space?

• By analyzing underwater currents

• By monitoring changes in ocean salinity

• By measuring the return speed and intensity of a radar pulse

• By recording atmospheric pressure changes