America's Galápagos: The ancient, sinking volcanic chain hidden northwest of Hawaii

Nature · Published 29 September 2026 Swipe more like this →

In short: Beyond the familiar shores of the main Hawaiian islands lies a remote, mostly uninhabited archipelago. These Northwestern Hawaiian Islands are the oldest remnants of a volcanic hotspot, serving as a vital sanctuary for millions of seabirds and unique marine life, largely untouched by the modern world's ecological footprint.

Formed between 7 and 30 million years ago, the Northwestern Hawaiian Islands are the geological ancestors of the main Hawaiian chain. As the Pacific Plate drifted northwest over a stationary volcanic hotspot, these islands were birthed as shield volcanoes. Over eons, they have undergone a slow, inevitable transformation: starting as high, rocky peaks, they gradually erode and subside, eventually becoming low-lying sandy islands and coral atolls before sinking beneath the waves as seamounts.

This process is governed by the Darwin Point, a threshold where coral growth can no longer keep pace with the island's subsidence. Kure Atoll currently sits at this critical boundary, marking the future fate of every island in the chain. Despite their harsh, isolated environment, these islands host an extraordinary level of biodiversity. The region contains 70 percent of all coral reefs in the United States and serves as a massive nursery for over 14 million seabirds representing 21 different species, earning it the nickname America's Galápagos.

The human history of these islands is equally distinct. While Ancient Hawaiians established permanent settlements on Nīhoa and utilized Necker for religious rituals, the islands were largely deserted by the time Europeans arrived in the 18th century. Unlike the main islands, which have been heavily altered by introduced species, the Northwestern islands remain mostly intact. Today, they are protected within the Papahānaumokuākea Marine National Monument, safeguarding endemic treasures like the Laysan duck and the Hawaiian monk seal from the exploitation that nearly destroyed them during the 19th and early 20th centuries.

The archipelago's geography is defined by its extreme isolation, situated thousands of miles from the nearest continents. This distance acted as a natural filter, allowing only species capable of long-distance flight or swimming to colonize the area. With over 1,700 endemic species found nowhere else on Earth, the islands offer a rare, preserved window into a natural world that has largely vanished elsewhere, providing scientists with an invaluable baseline for understanding island ecosystems.

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