<meta http-equiv="refresh" content="0; url=https://r.sealevelrise.org/https://sealevelrise.org/states/alaska/"/> Alaska's Sea Level Rise - Sea Level Rise

Overview

As Lands Rise, Alaska's Sea Level is Sinking

Although ice melt from Alaska contributes to global sea level rise, sea levels near Alaska have been decreasing because the land beneath the state is rising.1 | 2 Despite this, the state could see rising water in the future, as sea levels will eventually rise faster than the land. Alaska is still experiencing some of the effects of changing sea levels, like increased flooding and erosion, and some coastal villages are already relocating. The state will need to take action and plan for future sea level rise and flooding.

Measuring sea level rise

Since 1950, sea levels off Alaska’s coast have declined 32 inches.3 Scientists know this because the sea level is measured every 6 minutes using equipment like satellites, floating buoys off the coast, and tidal gauges to accurately measure the local sea level as it accelerates and changes.4

Created with Highcharts 6.2.0

Sea level measurement from Juneau area tide gauge since 1950

Causes & Complications

Why is Sea Level Rise Complicated in Alaska?

Sea levels off Alaska’s coast have been decreasing because the land beneath Alaska is rising due to shifts in the Earth’s tectonic plates and a process called glacial isostatic adjustment.2 Heavy glacial ice that once covered Alaska during the Ice Age put immense pressure on the land, pushing the land down and compressing it. While most of this heavy ice retreated a long time ago and was replaced by newer, lighter ice, the land is still adjusting from its loss of pressure and rising back to its original form.2

Think of it like a person laying down on a foam mattress; once that person gets up, an indentation from their body remains and the foam around where they were laying is lifted. After a while, the foam surrounding the indent lowers and the indentation rises, returning the mattress back to its original form. This is what’s happening to the land in Alaska as it returns to its original form.

Even though melting ice sheets in Alaska contribute to global sea level rise, that ice melt actually decreases sea levels off Alaska’s coast. This is because ice is heavy, so it has a strong gravitational pull that attracts water. As the ice melts in Alaska, it weighs less, and has a weaker pull on water. Without the gravitational pull from the heavy ice, water moves elsewhere, lowering sea levels near Alaska and increasing sea levels further away. Click here to learn more about the causes of sea level rise.

Ice Melt
How Ice Melt Increases Sea Level Rise

Forecast

What's the Future of Sea Level Rise?

It’s unclear whether Alaska will see more sea level rise in the future because scientific projections vary,5 with some showing a continued decrease and others showing an increase in sea level rise. The future will depend on how much the land beneath Alaska continues to rise, and how fast the ice melts.

Scientists are not certain how fast the ocean will warm and ice will melt. They expect water levels to continue to rise faster, but are not sure just how fast. Therefore scientists from the National Oceanic and Atmospheric Administration (NOAA) and the US Army Corps of Engineers (USACE) have made predictions based on ranges from low to high.

Below you can see the range of the NOAA and USACE high and intermediate forecasts for various locations around Alaska.5 Currently, the USACE high forecast, seen as the darkest red line, is the most likely projection.

Ketchikan
Created with Highcharts 6.2.0Ketchikan Sea Level Rise Forecasts

Costs

What's at Risk in Alaska?

Despite reduced rates of sea level rise, Alaska’s communities are still threatened by the effects of rising waters. Severe erosion and disappearing sea ice are causing communities in western Alaska to flood regularly. If the issue can’t be addressed, communities may have to leave their homes and move further inland.7 Some villages, such as Kivalina, Newtok, and Shishmaref, are already relocating, with an estimated cost of up to $400 million per village.7

What can you do?

Individuals, mayors, legislators, governors, and Congress can work together to build protections before flooding, to build back stronger after flooding, and to create plans that future-proof our communities. Click here to see what solutions can help protect your home or what your community can do.