Height of Uncertainty 

Are Moloka‘i’s sea cliffs really the world’s tallest?
Story by Kyle Ellison. Photos by PF Bentley.

“And here,” says the pilot, flying his helicopter along Moloka‘i’s northern coast, “is the highlight everyone’s been waiting to see: the tallest sea cliffs in the world.” It’s an oft-repeated superlative about Hawai‘i, a place already awash in superlatives (southernmost point in the United States, most isolated archipelago in the world, tallest mountain on Earth), that Moloka‘i boasts the tallest sea cliffs in the world.

Beginning in the 1970s, the north coast of Moloka‘i (seen here looking east toward Kalaupapa) held the Guiness world record for the tallest sea cliffs on Earth, peaking at Umilehi poing, elevation 3,330 feet (seen on the opening page). But Guiness stopped keeping that record in the 1990s, raising the question whether Molokai`s cliffs can still claim the title.

Moloka‘i’s north coast is indeed dramatic—a place where waterfalls spill from the clouds to the sea and sheer mountains end at the waterline as if cut by a knife. The cliffs deserve superlatives, but are they, in fact, the “world’s tallest sea cliffs”? It turns out that’s not a simple question to answer.

According to the Guinness Book of World Records, from the 1970s through the late 1990s, the technical record holder for the title were “the cliffs on the north coast of east Moloka‘i, near Umilehi point, which descend 3,330 feet to the sea at an average gradient greater than 55 degrees.” Guinness also says, however, that they “no longer monitor the record for highest sea cliffs.”

The ambiguity lies partly in the question of what, exactly, is a cliff? The American Geological Institute defines a cliff as “any high, very steep to perpendicular or over-hanging face of a rock.” National Geographic says “a cliff is a mass of rock that rises very high and is almost vertical, or straight up and down.” 

Beginning in the 1970s, the north coast of Moloka‘i (seen here looking east toward Kalaupapa) held the Guiness world record for the tallest sea cliffs on Earth, peaking at Umilehi poing, elevation 3,330 feet (seen on the opening page). But Guiness stopped keeping that record in the 1990s, raising the question whether Molokai`s cliffs can still claim the title.

That phrase, “almost vertical,” leaves quite a lot of leeway when it comes to classifying what is and isn’t a cliff; those on Moloka‘i, for example, ascend at fifty-five degrees, a far cry from “straight up and down.” While it’s true that Moloka‘i did once hold the record, decades have passed since the last time the records were updated and tall sea cliffs measured. 

Umilehi point sits between Wailau and Pelekunu valleys, about four miles east of the Kalaupapa peninsula. It’s a place where sea caves scallop the shoreline, and waves that reach over twenty feet unload on the rocks each winter. Ancient Hawaiians frequented the valleys to gather, farm and fish during bountiful times of the year, but very few humans have explored the cliffs. 

Stephen Perlman, however, is one of them. A botanist with the National Tropical Botanical Garden, Perlman has spent more time exploring Moloka‘i’s sea cliffs than perhaps anyone else on the planet. In his younger days (he’s now in his early seventies), he would kayak to spots on the northern coast and then scale the cliffs in search of rare plants. The area is inaccessible to invasive and destructive ungulates like pigs and deer; even goats can’t remain long in the steepest of spots. Because it’s so protected, the cliffs of Moloka‘i remain one of Hawai‘i’s most ecologically rich spots. 

According to Perlman (who often climbed without ropes), the cliffs in the area around Umilehi point are nearly vertical for the first thousand feet, but above that, he says, it’s more of a “steep slope,” but not so steep that he couldn’t camp overnight there. During his many expeditions, there were times when once he’d reached the steep part of the slope (after free climbing the vertical rock), he’d lash a climbing rope to an ‘ōhi‘a or lama tree and then swing horizontally across the cliff face to hand-pollinate rare plants. “Sure, it’s dangerous,” he says, “and yes, I guess you could fall, but it’s one of the most wonderful places that I’ve worked in my life.”

Sunrise turns the cliffs of Moloka‘i near Kalaupapa into a pastel tableau. Until every sea cliff in the world has been found and measured, it can’t be known with certainty whether Moloka‘i’s are the tallest. But for botanist Stephen Perlman, who spent much of his life exploring this coast, that hardly matters. "It’s just a detail," he says. "No one would doubt that they are absolutely spectacular."

John Sinton—emeritus professor of Earth sciences at the University of Hawai‘i at Mānoa—downplays the importance of the record, because records are by nature “ephemeral,” he says. “The cliffs on Moloka‘i will eventually erode away because that’s what volcanic islands do.” This might already have been going on for millions of years, and Sinton says it’s possible that east Moloka‘i once rose five thousand feet higher than the peaks we see today. Wind and waves have eroded the slopes, but the island has also subsided—that is, sunk—and rising seas have covered spots that once baked in the sun. 

About five miles north of the Kalaupapa peninsula, scientists (including Sinton) have studied the seafloor and found evidence of streambeds that currently sit nearly five thousand feet beneath sea level. There’s also evidence of an ancient shoreline on that underwater plain, so even if Molokai’s northern coast really does have the world’s tallest sea cliffs, there will likely come a day when even these towering cliffs will sink beneath the waves. 

That said, Sinton believes there might be more at play than erosion and subsidence. Given the slope of the drop and the fact that they shear in a more or less straight line, Sinton thinks the cliffs might be sitting on a fault line, or they could also be an artifact of the Wailau slide, a massive event that occurred 1.5 million years ago, when a huge chunk of Moloka‘i broke off and slid into the ocean. The slide took place a few miles north of the island and was so powerful it jettisoned rock over one hundred miles beneath water—one of the largest known landslides in Earth’s history—and generated a massive tsunami. Sinton says the most likely explanation for the cliffs’ formation is they’re “some form of structural response to the landslide that occurred offshore. … So we really don’t know when those cliffs were formed, or if they’re still forming today.” 

The dramatic landscape of northern Moloka‘i was likely formed by a combination of volcanic activity, plate tectonics and a massive landslide that occurred approximately 1.5 million years ago.

The cliffs of Moloka‘i might be slowly losing height, but there are other places where they are still rising, like the Qingshui cliffs that currently tower about 2,600 feet along Taiwan’s eastern coast. They’ve maintained their height, if not grown taller as the island evolves, and span an area over thirteen miles wide. In a 2006 interview with the New York Times, geophysicist Francis Wu noted that “Taiwan is one of the fastest rising mountains in the world,” where the peaks are actually gaining between two to three centimeters per year.(They’re also easier to experience, because unlike Moloka‘i’s isolated cliffs, which can be accessed only by air or sea, the Qingshui cliffs have a road clear across them, with sheer drop-offs and nerve-rattling views that visitor publications have likened to the feeling of “flying above the Pacific.”) 

Regardless of which mountains are sinking or growing, Sinton says “this whole business of records … I try to stay away from ‘this is the highest,’ because the only real way to answer that question is to review every cliff in the world.” 

Enter climber David Kaszlikowski, who along with his partner, Eliza Kubarska, seeks out virgin sections of wall in some of the world’s most isolated spots. In 2007—about a decade after Guinness stopped monitoring the title for the world’s tallest sea cliff—he and Kubarska successfully completed a climb up Greenland’s Maujit Qaqarssuasia, a.k.a. “the Thumbnail.” The cliff rises 5,148 feet out of blue, ice-flecked waters at an angle of slope more vertical than that of Umilehi. The team began climbing directly from their kayaks (which they’d used to access the site), and because the climb would take multiple days—and there wasn’t any shoreline—they hung the boats vertically above the water so they wouldn’t float away. 

Several other peaks around the world are in contention for the tallest sea cliff, like Maujit Qaqarssuasia, a 5,148-foot spire of solid granite also known as the Thumbnail, in South Greenland.

After their feat the alpine community was abuzz with news of the pioneering couple who had forged a new route up what Alpinist.com called “the highest sea cliff in the world.” Kaszlikowski, however, was not so sure, and additional research concluded that even Maujit Qaqarssuasia might not be the tallest sea cliff in the world. Another peak on the opposite side of the globe can make a strong case for the title—and this one is very well known. 

Rising 5,544 feet, Mitre Peak on New Zealand’s South Island is one of the most stunning, iconic features of Fiordland National Park. It presides over Milford Sound, which is lined on both sides by towering spires of sheer, glacially carved rock. While it doesn’t have vertical walls at the base in the same way Moloka‘i’s cliffs do, the average slope from summit to sea is steeper than that of Kalaupapa. Most consider Mitre Peak to be its own stand-alone “mountain,” but as it reaches its height at a steeper angle than other well-known “cliff” spots, who’s to say that it isn’t a “sea cliff” in addition to a “peak” or“mountain”? If so, Milford Sound has numerous other contenders. In his doctoral thesis at New Zealand’s University of Canterbury, JL Dykstra names six Milford Sound peaks that all rise higher than four thousand feet and “form steep (greater than forty-five-degree) sea cliffs that plunge directly into the fiord.”

The Qingshui cliffs of Taiwan aren’t even close in height to Moloka‘i’s — yet. One day in the distant future they could claim the title of world’s tallest: These cliffs are still rising, while Moloka‘i’s are eroding and subsiding into the ocean.

One of those is Mount Kimberly (a.k.a. “the Lion”), which has a steeper slope than Mitre Peak but reaches only 4,272 feet—still a thousand feet higher than Moloka‘i. Additionally, Kimberly’s first two thousand feet spring nearly vertically from the sea, whereas Moloka‘i’s cliffs are vertical for a mere thousand before shading into a very steep slope. Mount Kimberly raises the question: Should the term “sea cliff” be reserved solely for slopes of ninety degrees, or do coastal mountains with gentler slopes deserve to be in the running?

By that criterion, Prekestolen needs to be included in the discussion—as do its Nordic, coastal compatriots, Hornelen and Kjerag. Much like Greenland and Milford Sound, Norway is a place where glaciers and time have combined to create a serpentine shoreline of valleys, sea cliffs and fjords. While only 1,982 feet, Prekestolen (or “Pulpit Rock”) is famous among hikers, adventurers and BASE jumpers, who trek to the top for the chance to stand at the edge of a gut-churning vertical drop. Like the world’s largest stone diving board, the rock at Prekestolen juts out from a cliff where those with the courage to walk toward the edge will find themselves on a promontory, surrounded on three sides by the nearly two-thousand-foot drop. Prekestolen is much lower than Hornelen, which is generally regarded as Europe’s highest sea cliff at 2,821 feet. Its angle of slope is similar to that of Moloka‘i’s mountains, although unlike the cliffs behind Kalaupapa, which few have experienced on foot, hiking up Hornelen has become one of Norway’s most popular visitor activities.

Mitre Peak rises above New Zealand’s Milford Sound and towers more than two thousand feet higher than Moloka‘i’s cliffs. But Mitre Peak was carved by glaciers and its walls enter a fjord, creating contention around whether it can be called as a true sea cliff.

Both, however, are lower still than Kjerag, a mountain that towers 3,640 feet above Norway’s Lysefjorden. Even though it’s considered a mountain, its northern face has a vertical cliff that drops 3,228 feet to the placid waters below. That’s just as high as Moloka‘i, and there isn’t any slope—it falls directly to the sea.

That word, “sea”—as much as “cliff”—lies at the heart of this entire question. It also might be the technicality that helps put Moloka‘i back on top. Yes, Kjerag is just as high, and yes, Mitre Peak and Maujit Qaqarssuasia dwarf Moloka‘i by thousands of feet, but can any of them actually be classified as “sea” cliffs, considering they rise up from fjords? The US Department of Agriculture Natural Resources Conservation Service defines a fjord as “a long, narrow, winding, glacially eroded, U-shaped and steep-walled, generally deep inlet or arm of the sea between high rocky cliffs of slopes along a mountainous coast.” Moloka‘i’s cliffs are exposed to the sea, whereas cliffs like those in Norway and Milford are tucked away in those “arms of the sea,” so do those spots really count?  

When asked that question, Dominique Weis of the Department of Earth, Ocean, and Atmospheric Sciences at the University of British Columbia also references the American Geological Institute’s definitions. In its glossary of terms, it states that a sea cliff is an “erosional landform, produced by wave action, which is either at the seaward edge of the coast or at the landward side of a wave-cut platform and which denotes the inner limit of the beach erosion.” By that definition the cliffs of a fjord don’t count because they are partially formed by glacial erosion—not by waves. Then again, Moloka‘i’s sea cliffs aren’t solely the result of wave action either, as they might be linked to a tectonic fault and/or a massive prehistoric landslide. 

Though ancient Hawaiians frequented the valleys of northern Moloka‘i to gather, farm and fish during certain times of the year, very few modern humans have ever explored the cliffs.

So if a sea cliff must face out toward the sea—and it gets bonus points for being nearly vertical—maybe that’s the reason some Faroe Islands visitor groups are able to justify online claims that the 2,488-foot Cape Enniberg is “the world’s tallest vertical sea cliff.” It rises up from the North Atlantic in an island group set between Iceland and Norway, and while lower in elevation than Hornelon, Qingshui and Moloka‘i (all of which face toward the sea), its wall is nearly vertical, whereas the rest have that dubious angle of slope.

Because there’s no set angle that defines a cliff, however, should Moloka‘i still claim the title? For Perlman the entire discussion is moot. “Look at a record like ‘the rainiest place on Earth,’” he laughs. Two Hawai‘i locations, Wai‘ale‘ale on Kaua‘i and Big Bog on Maui, are often in the running for that distinction. “Are they really the rainiest places on Earth, or just the rainiest with a rain gauge? Whether Moloka‘i’s sea cliffs are the highest in the world—really that’s just a detail. No one would doubt they’re absolutely spectacular.” HH