Tourist Spot

Plymouth Rock images don’t prove sea level is the same as it was in 1620

Legend has it that upon arriving in North America, the Pilgrims descended from the Mayflower onto the large rock that now stands in a prominent location on the waterfront of Plymouth, Massachusetts.

Plymouth Rock is a well-known tourist attraction, but its connection to early US history is unproven. And despite what some social media users have claimed, the landmark cannot be used to refute that sea levels are rising.

An Instagram user shared a July 17 meme on the rock that read, “Plymouth Rock, 2022 still at sea level.”

On July 12, a Facebook user shared another meme with two photos of Plymouth Rock side by side, one labeled “1620 at sea level” and the other “2022 still at sea level.”

(Screenshot/Facebook)

The posts were flagged as part of Facebook’s efforts to combat fake news and misinformation on its News Feed. (Learn more about our partnership with Facebook.)

These Plymouth Rock memes don’t prove sea levels stay the same; the messages are false and misleading.

This circa 1869 engraving titled “Landing of the Pilgrims on Plymouth Rock, 1620” made available by the Library of Congress depicts a woman being helped disembark from a small boat held in position against a rock by men with ropes and poles. In the background on the right, other pilgrims kneel in prayer. (Peter Frederick Rothermel, Joseph Andrews/Library of Congress via AP)

There is no evidence that the rock proudly displayed under Plymouth’s portico today is the exact spot where Pilgrims first landed the Mayflower at Plymouth, let alone that it was found at the sea. (The Pilgrims first landed at Provincetown, Massachusetts on November 11, 1620. The Mayflower anchored in Plymouth Harbor a few weeks later.)

There are two main accounts of the landing of the Pilgrims at Plymouth, but “both simply say that the Pilgrims landed. Neither mentions rocks in their account of the landing,” said the website of the Pilgrim Hall Museum in Plymouth. “The earliest references to Plymouth Rock are found over 100 years after the actual landing.”

The National Museum of American History website refers to the story of the Pilgrims’ landing at Plymouth Rock as “oral tradition”, and said that no contemporary account of the landing mentions a rock.

The Plymouth Tourism website said that in 1741 an elder identified Plymouth Rock as the exact landing point. Although the veracity of the elder’s claim is unknown, Plymouth Rock “quickly became an American icon”, the site added.

On this Sunday, November 18, 2018, photo visitors stand in a pavilion while gazing at Plymouth Rock, in Plymouth, Mass. (AP Photo/Steven Senne)

Once the rock was identified as Plymouth Rock, its nomadic history began.

“In 1774, a team attempted to move the rock from the shore and place it next to Plymouth’s Liberty Pole in the town square,” the National Museum of American History said. “Before it could be pulled from the beach, it accidentally broke in two.”

Part of the rock remained in place; the other room was moved to the town square.

More than 100 years later, in 1880, “the two pieces were brought together on the shore and cemented together,” the National Museum of American History said. In most images of the rock it is easy to see where it has been fused together. The Pilgrim Hall Museum website states that “1620” was also cut from Plymouth Rock in 1880.

In 1920, the rock was moved again, when Plymouth’s waterfront was redesigned and the shoreline rebuilt, according to the Pilgrim Hall Museum website.

The rock has also been under water before, during extreme Weather report and exceptionally high tides called royal tides.

Additionally, experts said the rock was not a useful benchmark for measuring changes in sea level.

Michael Oppenheimer, professor of geosciences and international affairs at Princeton University, said a single stationary object “anchored in bedrock and free of tectonic activity” can sometimes be used to measure sea level. local.

“But all it can tell is local sea level, not ‘sea level’ in general or global average elevation,” Oppenheimer said. Local sea level rise can differ significantly from global average sea level rise due to land subsidence or tectonic activity, he said.

Gary Griggs, professor of earth sciences at the University of California, Santa Cruz, said the National Oceanic and Atmospheric Administration has been monitoring sea level relative to land in Boston, near Plymouth Rock, for 100 years. . These records show that sea level has risen about 11.4 inches over the past century.

Satellite data, which has been used to measure sea level rise since 1993, indicates an average rate of global sea level rise of about 13.9 inches per century, Griggs said. This rhythm is accelerating; over the past decade, the rate has increased to about 19.7 inches per 100 years, he said.

“It’s a relatively simple science, and there are no alternative interpretations or facts,” Griggs said. “Sea level rise is directly linked to global warming. The warmer the planet, the more the sea water expands and the more the ice melts, which raises the sea level.

Oppenheimer also said that global average sea level is rising every year and that rise is accelerating. “There’s no doubt about it,” he said.

Sea level rise is causing problems, some of which have already begun, Oppenheimer said.

“So-called storm or fair weather flooding has increased in frequency, meaning high tides now regularly flood streets along the coast in many states – up to 10 times more frequently than there are. 50 years,” he said. “Additionally, during large coastal storms, the risk of flooding increases as water penetrates further inland and at higher elevations.”

There is no evidence that Plymouth Rock was at sea level when it might have welcomed pilgrims in 1620. The rock has also shifted several times over the past 400 years and is sometimes submerged during high tides and extreme weather conditions. Experts have said that Plymouth Rock is not useful for assessing sea level changes. That sea level is rising, however, is undisputed.

We rate this claim as false.

This fact check was originally published by PolitiFact, part of the Poynter Institute. It is republished here with permission. See the sources here and more of their fact checks here.