A small new world has materialized on the shores of the Big Island of Hawaii. The 20-by-30-foot expanse is a geological tabula rasa, untouched and unlike just about anywhere else on Earth.

The island first emerged Thursday from lava flowing out of a new fissure that opened on Hawaii’s Kilauea volcano in May, according to the U.S. Geological Survey. The agency said underwater pressure forced the lava flowing northeast from the vent to the surface. A Hawaiian Volcano Observatory crew noticed the mass during a flight Friday morning.

One of the most active volcanoes worldwide, Kilauea has erupted virtually continuously for the last 35 years and with great intensity over the past several months. In June, molten rock smothered a neighborhood called Vacationland. And on Monday, a basketball-size lava bomb smashed through the roof of a sightseeing boat, injuring more than 20 people.

The cascade of eruptions and earthquakes marks heightened volcanic activity in recent months. Two vents — chambers that allow lava to escape — shut down, causing a lava lake at the volcano’s summit to drain, said Michael Garcia, a volcanologist at the University of Hawaii’s Manoa campus in Honolulu who has been studying Kilauea since its current phase of eruptions began in 1983. “So now we have at the summit a series of daily explosions. Every single day. Boom. Boom. It’s a progressive collapse of the summit.”

The lava feeding these vents drained away, Garcia said, and it is now feeding a vent in the Leilani Estates subdivision near the southeastern tip of Hawaii. New fissures in the earth are emitting streams of molten rock, forcing evacuations as fire engulfed homes in the rural district where property is relatively cheap but life is hazardous. About 700 houses have been destroyed since May, according to the Hawaii Tribune-Herald.

But property damage is not the only consequence of eruptions. Volcanic activity can drive structural transformation of oceanic islands like Hawaii and Tahiti, Garcia said.

Across the world, other causes of island formation include erosion and glacial retreat. Shelly Island, a crescent-shaped sandbar, began forming in spring 2017 in the Outer Banks of North Carolina but disappeared by early 2018. Uunartoq Qeqertaq, Greenlandic for “the Very Hot Island,” became detached from mainland Greenland in 2005 as a result of retreating ice shelves.

Whether the tiny new mass off the coast of Hawaii survives is an open question, scientists said. Crucial factors include how long the new eruptions last and the sort of surface that takes shape: hard lava, which is likely to last long enough to invite plant and animal colonization; or ash, which is more susceptible to erosion.

“I think we can expect the unexpected,” Garcia said. “If the newest eruption were to stop in the near future, the island would erode away. But if the eruption continues, and the bay fills in, it’s likely that the coastline could move out to this island, and you could have an expanded coastline.”

Should the island survive, it would be an opportunity to study how life inhabits a new area — a blank slate that would be a chance for earth scientists to pose novel questions about the ground we occupy, or don’t. “How does life arrive at new places and develop?” Garcia said, envisioning the opportunities that might await researchers. “It’s a wonderful mystery and one we’re still challenged in fully appreciating.”

He tempered his expectations: “It may very well not survive long enough to support life and see it change. We’ve had this a lot in Japan — a volcano will erupt, form a new island, and before long it’s gone.”

New islands are becoming rarer in an era of rising sea levels, said Alastair Bonnett, a professor of social geography at Britain’s Newcastle University and the author of “Beyond the Map: Unruly Enclaves, Ghostly Places, Emerging Lands and Our Search for New Utopias.”

These days, islands most often make headlines because they are disappearing, not coming to life. The phenomenon of vanishing islands is so pronounced that it forms the basis of a special tourism pitch. The website Jetsetter advertises “8 Islands to Visit Now Before They Disappear.” Mother Jones asks whether Tuvalu, a Polynesian island nation made up of coral atolls reminiscent of Gauguin’s paintings of the South Seas, will “become a modern Atlantis.”

There is no absence of new islands to take the place of those that disappear, but a number of the new arrivals are artificial, such as Deira Island off the coast of Dubai or a fleet of man-made islands hosting Chinese military equipment in the South China Sea.

Far from being man-made, Hawaii’s new island caught everyone by surprise. It doesn’t even have a name. And Hawaii officials said this week that there were indications that the island was already becoming a peninsula, attaching itself to the main island, according to Hawaii News Now.

Fissure 8 is the provisional name for the vent that is discharging the lava forming the new land mass. A member of the Hawaii County Council this month introduced a resolution asking the State Board on Geographic Names “to consult with community members who have direct traditional, cultural, and familial ties to the district of Puna to establish an appropriate name for the Fissure 8 vent.”

Bonnett said new volcanic islands are noteworthy not just because “they are spectacular but also because they are not at all common. About three-quarters of the world’s molten magma comes from under the sea, but it takes a lot to make an island.”

“New islands carry a kind of hope and a sense of fresh beginning,” Bonnett said. “New islands disrupt our sense of orderly geography, which is also why they fascinate us, even tiny ones. We can barely believe that land can be created right in front of our eyes — it feels like a kind of magic. We remain wedded to the notion — despite all the counter-evidence — that our planet is an immobile lump.”

It is “no coincidence,” Bonnett said, that Thomas More chose an island as the setting for his 1516 sociopolitical satire “Utopia,” which coined the term for a place in which everything is perfect. The neologism draws on the Greek ou-topos, meaning “no place or “nowhere,” and eu-topos, meaning “good place.” It connotes an unfinished, ideal project — maybe unattainable, but maybe not.