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Understanding Sea Level

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  • Ice Melt
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The oceans form an integral part of the global water cycle: precipitation, evaporation, and rivers move large amounts of water between land and the oceans. Since the amount of water on Earth doesn’t change, a change of the amount of water in one component must be offset against the other. Because the water cycle varies over time, the amount of water stored in the ocean varies over time as well. For example, heavy rains over Australia, Southeast Asia, and the Amazon Basin -- and the subsequent storage of large amounts of water on land -- caused a drop in global sea level of 1 centimeter during the 2010-2011 La Niña cycle.

Humans also directly change the amount of water on land, and thus the amount of water in the oceans. The global construction of large dams in rivers has led to the impoundment of an amount of water equal to 3 centimeters of sea level. On the other hand, in many places, groundwater from non-recharging aquifers is consumed by human civilization, and this water eventually ends up in the oceans, adding to global sea-level rise.

  • Overview
  • Ice Melt
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Top Stories

Thinning and calving both contribute to the loss of ice shelves in the Antarctic, but how to they affect sea level?
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How Ice-Shelf Loss Drives Sea Level Rise
How Ice-Shelf Loss Drives Sea Level Rise
Scientific assessments are designed to help island residents cope with potential threats from sea level rise.
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NASA-UN Partnership Gauges Sea Level Threat to Tuvalu
NASA-UN Partnership Gauges Sea Level Threat to Tuvalu
A look into the causes and effects of accelerating sea level rise unique to the Southeast Coast.
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Why Seas are Rising Faster on the Southeast Coast
Why Seas are Rising Faster on the Southeast Coast
Kelvin waves, a potential precursor of El Niño conditions in the ocean, are rolling across the equatorial Pacific toward the coast of South America.
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International Sea Level Satellite Spots Early Signs of El Niño
International Sea Level Satellite Spots Early Signs of El Niño
Floating sea ice seems to have a small effect on sea level.
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Melting Ocean Ice Affects Sea Level – Unlike Ice Cubes in a Glass
Melting Ocean Ice Affects Sea Level – Unlike Ice Cubes in a Glass
Sea level science team reveals complex, interlocking causes behind "nuisance" flooding events.
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NASA Project Shows Hidden Factors Shape Minor Coastal Floods
NASA Project Shows Hidden Factors Shape Minor Coastal Floods

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News & Features

    • Sea Level News
    • Scientist Interviews
    • News Briefs

Understanding Sea Level

    • Overview
    • Global Sea Level
    • Regional Sea Level
    • By the Numbers
    • Key Indicators

Science Team

    • Overview
    • Projects
    • Team Members
    • Presentations

Climate Tools

    • IPCC AR6 Sea Level Projection Tool
    • Flooding Analysis Tool
    • Interagency Sea Level Rise Scenario Tool
    • Sea Level Evaluation & Assessment Tool
    • All Climate Tools

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    • Virtual Earth System Laboratory
    • All Analysis Tools

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