Plus, 5 places in the U.S. where you can visit a ghost forest.

Along the Seward Highway near Girdwood, Alaska, you can see a ghost forest that was swamped with saltwater during the 1964 earthquake.

You probably have seen a ghost — a ghost forest, that is.

A ghost forest is found along coastlines and occurs when sea levels rise and flood healthy forests with saltwater. The sea water mixes with the freshwater that deciduous and evergreen trees need for survival. The saltwater poisons the trees, eventually killing them and leaving a forest of skeletons behind.

Ghost forests are a haunting indicator of climate change, and a new study published in Nature Climate Change finds they're more widespread along the Atlantic Coast of the U.S. than ever before. Over the past century, sea levels have risen 5 to 8 inches, but the rate at which they are rising is increasing. By 2100, they're expected to rise anywhere from 1.3 to 3.9 feet, which means we'll see even more land submerged.

This effect is amplified along the East Coast because some of the land is sinking. As the National Oceanic and Atmospheric Administration (NOAA) explains:

Even though the ice retreated long ago, North America is still rising where the massive layers of ice pushed it down. The U.S. East Coast and Great Lakes regions — once on the bulging edges, or forebulge, of those ancient ice layers — are still slowly sinking from forebulge collapse.

"In rural, low-lying areas, there are so many dead trees and farmland that's either stressed or abandoned that the signs of sea level rise are obvious," Matthew Kirwan, a professor at William & Mary's Virginia Institute of Marine Science and author of the study, told Popular Science.

5 ghost forests in the U.S.

Neskowin Ghost Forest in Oregon is best viewed during low tide.

1. Neskowin Beach, Oregon: During low tide at Neskowin Beach on Oregon's Tillamook Coast, a ghost forest emerges from the water. Hundreds of years ago, a forest of cedar and sitka spruce trees filled this area. But around 1700, a massive 9.0-magnitude earthquake destroyed them. Strong storms in 1997 and 1998 further eroded the beach, unearthing about 100 stumps.

A ghost forest along the Copalis River in Washington state was formed after a massive earthquake in January 1700.

2. Copalis River, Washington: That earthquake in 1700 hit in the Pacific Ocean and triggered floods in the Pacific Northwest. The land along the Copalis River in Washington, where a grove of red cedar and spruce trees stood, dropped about six feet. The forest was inundated with saltwater and killed, but some of the remains still stand today.

3. Girdwood, Alaska: Pictured at the top of the page is a ghost forest along Seward Highway near Girdwood, Alaska, that formed after a devastating earthquake in 1964. The ground in this area sank 5 to 9 feet, and at high tide, the entire town called Portage ended up below sea level. A few ghost forests were created, and if you visit, apparently you can still see portions of the buildings underwater.

When the Colorado River in Texas was dammed to form Inks Lake, a forest was immersed in water and killed, resulting in a ghost forest.

4. Inks Lake State Park, Texas: In the mid-1930s, the Inks Dam was built on the Colorado River to form Inks Lake. In the process, a forest was flooded and the bare trunks still can be seen in the lake today. Kayaking through it can give you a great up-close view of wildlife.

Boneyard Beach on Bulls Island, South Carolina, is appropriately named.

5. South Carolina's barrier islands: They don't call it Boneyard Beach for nothing. It's a ghost forest located on Bulls Island, one of South Carolina's barrier islands. Rising sea levels and eroding shore lines formed the ghost forest on this and other barrier islands. Plus, the trees have been bleached by the sun, giving them a truly ghost-like appearance.