Sea Level Rise - Blog Posts

Rocket Launches and Rising Seas

At NASA, we’re not immune to effects of climate change. The seas are rising at NASA coastal centers – the direct result of warming global temperatures caused by human activity. Several of our centers and facilities were built near the coast, where there aren’t as many neighbors, as a safety precaution. But now the tides have turned and as sea levels rise, these facilities are at greater risk of flooding and storms.

Global sea level is increasing every year by 3.3 millimeters, or just over an eighth of an inch, and the rate of rise is speeding up over time. The centers within range of rising waters are taking various approaches to protect against future damage.

Kennedy Space Center in Florida is the home of historic launchpad 39A, where Apollo astronauts first lifted off for their journey to the Moon. The launchpad is expected to flood periodically from now on.

Like Kennedy, Wallops Flight Facility on Wallops Island, Virginia has its launchpads and buildings within a few hundred feet of the Atlantic Ocean. Both locations have resorted to replenishing the beaches with sand as a natural barrier to the sea.

Native vegetation is planted to help hold the sand in place, but it needs to be replenished every few years.

At the Langley Research Center in Hampton, Virginia, instead of building up the ground, we’re hardening buildings and moving operations to less flood-prone elevations. The center is bounded by two rivers and the Chesapeake Bay.

The effects of sea level rise extend far beyond flooding during high tides. Higher seas can drive larger and more intense storm surges – the waves of water brought by tropical storms.

In 2017, Hurricane Harvey brought flooding to the astronaut training facility at Johnson Space Center in Houston, Texas. Now we have installed flood resistant doors, increased water intake systems, and raised guard shacks to prevent interruptions to operations, which include astronaut training and mission control.

Our only facility that sits below sea level already is Michoud Assembly Facility in New Orleans. Onsite pumping systems protected the 43-acre building, which has housed Saturn rockets and the Space Launch System, from Hurricane Katrina. Since then, we’ve reinforced the pumping system so it can now handle double the water capacity.

Ames Research Center in Silicon Valley is going one step farther and gradually relocating farther south and to several feet higher in elevation to avoid the rising waters of the San Francisco Bay.

Understanding how fast and where seas will rise is crucial to adapting our lives to our changing planet.

We have a long-standing history of tracking sea level rise, through satellites like the TOPEX-Poseidon and the Jason series, working alongside partner agencies from the United States and other countries.

We just launched the Sentinel-6 Michael Freilich satellite—a U.S.-European partnership—which will use electromagnetic signals bouncing off Earth’s surface to make some of the most accurate measurements of sea levels to date.

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Check out tiny-house-looking satellite Sentinel-6 Michael Freilich

It might look like something you’d find on Earth, but this piece of technology has a serious job to do: track global sea level rise with unprecedented accuracy. It’s #SeeingTheSeas mission will:

Provide information that will help researchers understand how climate change is reshaping Earth's coastlines – and how fast this is happenin.

Help researchers better understand how Earth's climate is changing by expanding the global atmospheric temperature data record

Help to improve weather forecasts by providing meteorologists information on atmospheric temperature and humidity.

Tune in tomorrow, Nov. 21 at 11:45 a.m. EST to watch this U.S.-European satellite launch to space! Liftoff is targeted for 12:17 p.m. EST. Watch HERE. 

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Sea Level Rise is on the Rise

As our planet warms, sea levels are rising around the world – and are doing so at an accelerating rate. Currently, global sea level is rising about an eighth of an inch every year.

That may seem insignificant, but it’s 30% more than when NASA launched its first satellite mission to measure ocean heights in 1992 – less than 30 years ago. And people already feel the impacts, as seemingly small increments of sea level rise become big problems along coastlines worldwide.

Higher global temperatures cause our seas to rise, but how? And why are seas rising at a faster and faster rate? There are two main reasons: melting ice and warming waters.

 The Ice We See Is Getting Pretty Thin

About two-thirds of global sea level rise comes from melting glaciers and ice sheets, the vast expanses of ice that cover Antarctica and Greenland. In Greenland, most of that ice melt is caused by warmer air temperatures that melt the upper surface of ice sheets, and when giant chunks of ice crack off of the ends of glaciers, adding to the ocean.

In Antarctica – where temperatures stay low year-round – most of the ice loss happens at the edges of glaciers. Warmer ocean water and warmer air meet at the glaciers’ edges, eating away at the floating ice sheets there.

NASA can measure these changes from space. With data from the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, scientists can measure the height of ice sheets to within a fraction of an inch. Since 2006, an average of 318 gigatons of ice per year has melted from Greenland and Antarctica’s ice sheets. To get a sense of how big that is: just one gigaton is enough to cover New York City’s Central Park in ice 1,000 feet deep – almost as tall as the Chrysler Building.

With the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission -- a partnership with the German Research Centre for Geosciences -- scientists can calculate the mass of ice lost from these vast expanses across Greenland and Antarctica.

It’s not just glaciers in Antarctica and Greenland that are melting, though. Nearly all glaciers have been melting in the last decade, including those in Alaska, High Mountain Asia, South America, and the Canadian Arctic. Because these smaller glaciers are melting quickly, they contribute about the same amount to sea level rise as meltwater from massive ice sheets.

The Water’s Getting Warm

As seawater warms, it takes up more space. When water molecules get warmer, the atoms in those molecules vibrate faster, expanding the volume they take up. This phenomenon is called thermal expansion. It’s an incredibly tiny change in the size of a single water molecule, but added across all the water molecules in all of Earth’s oceans – a single drop contains well over a billion billion molecules – it accounts for about a third of global sea level rise.

So Much to See

While sea level is rising globally, it’s not the same across the planet. Sea levels are rising about an eighth of an inch per year on average worldwide. But some areas may see triple that rate, some may not observe any changes, and some may even experience a drop in sea level. These differences are due to ocean currents, mixing, upwelling of cold water from the deep ocean, winds, movements of heat and freshwater, and Earth’s gravitational pull moving water around. When ice melts from Greenland, for example, the drop in mass decreases the gravitational pull from the ice sheet, causing water to slosh to the shores of South America.

That’s where our view from space comes in. We’re launching Sentinel-6 Michael Freilich, an international partnership satellite, to continue our decades-long record of global sea level rise.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Sea Level Rise is on the Rise

As our planet warms, sea levels are rising around the world – and are doing so at an accelerating rate. Currently, global sea level is rising about an eighth of an inch every year.

That may seem insignificant, but it’s 30% more than when NASA launched its first satellite mission to measure ocean heights in 1992 – less than 30 years ago. And people already feel the impacts, as seemingly small increments of sea level rise become big problems along coastlines worldwide.

Higher global temperatures cause our seas to rise, but how? And why are seas rising at a faster and faster rate? There are two main reasons: melting ice and warming waters.

 The Ice We See Is Getting Pretty Thin

About two-thirds of global sea level rise comes from melting glaciers and ice sheets, the vast expanses of ice that cover Antarctica and Greenland. In Greenland, most of that ice melt is caused by warmer air temperatures that melt the upper surface of ice sheets, and when giant chunks of ice crack off of the ends of glaciers, adding to the ocean.

In Antarctica – where temperatures stay low year-round – most of the ice loss happens at the edges of glaciers. Warmer ocean water and warmer air meet at the glaciers’ edges, eating away at the floating ice sheets there.

NASA can measure these changes from space. With data from the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, scientists can measure the height of ice sheets to within a fraction of an inch. Since 2006, an average of 318 gigatons of ice per year has melted from Greenland and Antarctica’s ice sheets. To get a sense of how big that is: just one gigaton is enough to cover New York City’s Central Park in ice 1,000 feet deep – almost as tall as the Chrysler Building.

With the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission – a partnership with the German Research Centre for Geosciences – scientists can calculate the mass of ice lost from these vast expanses across Greenland and Antarctica.

It’s not just glaciers in Antarctica and Greenland that are melting, though. Nearly all glaciers have been melting in the last decade, including those in Alaska, High Mountain Asia, South America, and the Canadian Arctic. Because these smaller glaciers are melting quickly, they contribute about the same amount to sea level rise as meltwater from massive ice sheets.

The Water’s Getting Warm

As seawater warms, it takes up more space. When water molecules get warmer, the atoms in those molecules vibrate faster, expanding the volume they take up. This phenomenon is called thermal expansion. It’s an incredibly tiny change in the size of a single water molecule, but added across all the water molecules in all of Earth’s oceans – a single drop contains well over a billion billion molecules – it accounts for about a third of global sea level rise.

So Much to See

While sea level is rising globally, it’s not the same across the planet. Sea levels are rising about an eighth of an inch per year on average worldwide. But some areas may see triple that rate, some may not observe any changes, and some may even experience a drop in sea level. These differences are due to ocean currents, mixing, upwelling of cold water from the deep ocean, winds, movements of heat and freshwater, and Earth’s gravitational pull moving water around. When ice melts from Greenland, for example, the drop in mass decreases the gravitational pull from the ice sheet, causing water to slosh to the shores of South America.

That’s where our view from space comes in. We’re launching Sentinel-6 Michael Freilich, an international partnership satellite, to continue our decades-long record of global sea level rise.

Red areas in this map represent large projected increases in the frequency of floods following 10 centimeters (four inches) of additional sea-level rise.

According to a study, stark increases in instances of flooding are projected for Pacific islands, parts of Southeast Asia, and coastlines along India, Africa, and South America in the years and decades ahead — before spreading to engulf nearly the entire tropical region.

Unlike vulnerable cities and towns along the East Coast of the U.S., where frequent storms and big waves lead to large variations in day-to-day water levels, tropical coastlines tend to be surrounded by waters with depths that vary less. That means many tropical coastlines were not built to withstand the kinds of routine flooding that will be caused by rising seas.

- Upton, J. (2017, May18). Rising seas are lapping at the shores of the world’s poorest countries. Grist. 

Everglades (and south Florida, including Miami) with 5ft of sea level rise

Everglades (and south Florida, including Miami) with 4ft of sea level rise

Everglades (and south Florida, including Miami) with 2ft of sea level rise

The Florida Everglades, where elevation above sea level is often measured in single digits, is on of the most susceptible areas of the country to sea level rise. In addition to its low coastal elevation, the Everglades are threatened as a result of a history of wetland degradation that changed the way water flowed through the large wetland system. Restoring natural freshwater flows will help protect the everglades from the intrusion of salt water due to sea level rise, but it must be done quickly.

Dr. Harold Wanless of the University of Miami Department of Geological Sciences created a series of maps showing the Everglades under varying scenarios of sea level rise. This is the Everglades in 1995. 

Change in mean sea level over the past two decades. The lull in 2011 was the result of La Nina, not a pause in climate change.

Land use change on Cape Cod. This image shows a dramatic increase in development on the Cape from the 1950s into the twenty-first century. This is problemmatic, as the increased development leads to loss of native habitats and an increase in water pollution. The latter is largely a result of the fact that very little development is connected to sewers, and nitrogen from septic systems quickly leaches through the sandy soils into ponds, streams and bays.

Further, development is threatened by climate change; specifically sea level rise and increased costal erosion .

A study of "fossil beaches", those areas where geology and fossils show they were once pre-historic coasts, is aiming to give us a better picture of the threat of sea level rise. Researchers acknowledge that, even during natural climatic shifts, carbon dioxide is the primary driver of global warming and cooling. During the Pliocene, carbon dioxide was at 400ppm and sea level was much higher. We are currently at 393ppm and rising. We are likely to cross over 400ppm in the next several years. Thus, looking at sea level rise during the Pliocene can give us a picture of what sea levels may look like as a result of current global warming. This map shows where the coastline was in the U.S. during the Pliocene.

Predicted land change along the Louisiana coast over the next 50 years if we do nothing more than we have done to date. Red indicates areas likely to be lost, and green indicates areas of new land. This map is based on assumptions about increases in sea level rise, subsidence, and other factors.

The global rise in mean sea level is complicated in the Mississippi River Delta region by subsidence (sinking land). The Gulf of Mexico has one of the highest rates of subsidence in the nation due to sediment compaction and the extraction of groundwater, oil and natural gas. Restoration of the deltaic system can help stabilize shorelines and reduce the associated risks with rising sea levels. Deltas are formed by the constant inflow of sediment from rivers. However, the Mississippi River Delta has been cut off from this natural process through the construction of extensive levee systems for navigation and flood protection. Through planned sediment diversions, the natural deltaic process can be restored and help increase the resiliency of coastal areas.