Yellowstone Caldera Chronicles: What do Yellowstone and Hawaiʻi have in common? More than you might think

“Yellowstone Caldera Chronicles” is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This contribution is from Mark Stelten, research geologist with the U.S. Geological Survey and deputy scientist-in-charge of the Yellowstone Volcano Observatory.

Yellowstone and the Hawaiian Islands are some of the most spectacular examples of active volcanic systems in the world, each drawing millions of visitors annually.

These volcanic systems are separated by more than 3,000 miles and have dramatically different behaviors and appearances.

Yellowstone doesn’t produce tall volcanic features, but instead forms large depressions in the ground, referred to as calderas, because of explosive eruptions of rhyolite magma. After formation, Yellowstone’s calderas tend to fill with viscous rhyolite lava flows and domes that from broad plateaus or steep dome-like structures that are often covered with lodgepole pine trees.

In contrast, volcanic activity in Hawai‘i tends to build broad shield volcanoes such as Mauna Loa — the largest active volcano on Earth — that are composed of numerous fluid lava flows and stand above the surrounding landscape.

Hawaiian volcanoes are often capped by calderas, albeit much smaller than those produced by Yellowstone, that formed by collapse because of emission of lava flows rather than an explosive eruption. Hawaiian volcanoes also erupt much more frequently than Yellowstone, typically producing fluid basalt lavas, but individual eruptions tend to be much smaller than those from Yellowstone.

Despite these differences in eruptive behavior and outward appearance, Yellowstone and Hawai‘i have some deeply rooted similarities.

Most volcanic systems around the world are related to either subduction zones, where one crustal tectonic plate slides under another — as beneath the Cascade Range in the western United States — or at divergent plate margins, where magma ascends as the crust is being pulled apart — often in the middle of ocean basins such as along the mid-Atlantic Ridge.

Volcanism in Hawai‘i and Yellowstone, however, is instead driven by mantle plumes, regions where Earth’s mantle is anomalously hot and buoyantly upwelling.

As the hot mantle rises to shallower depths, it causes melting that in turn leads to the development of a magmatic system which can produce volcanic eruptions.

Mantle plumes operate independently of plate tectonics and remain mostly stationary as the Earth’s tectonic plates move above them. As a result, magmatic systems such as those in Hawai‘i and Yellowstone produce chains of volcanoes that have an age progression along their lengths.

During the past 16 million years, the hot spot feeding Yellowstone caldera produced several caldera systems extending from McDermitt Caldera in southeastern Oregon and northern Nevada to Yellowstone caldera in northwest Wyoming.

Each of these now-buried volcanic systems was similar to Yellowstone caldera in that they produced large explosive eruptions before plate motion carried the system far enough away from the hot spot that access to the mantle plume was cut off. Eventually, a new volcanic center formed to the northeast of the previous one above the new crustal location of the mantle plume.

The eastern Snake River Plain of southern Idaho marks this chain of “ancient Yellowstones” that gets older as you move to the southwest from Yellowstone caldera.

Similarly, the hot spot under Hawai‘i is responsible for producing the Hawaiian Ridge-Emperor Seamount chain during the past 80 million years. Volcanoes in that chain get older the farther northwest you go across the Pacific Ocean from the Hawaiian Islands.

The oldest “ancient Hawai‘is” are located off the coast of Kamchatka, Russia.

Given that Yellowstone and Hawai‘i are both powered by mantle plumes, why do these volcanic systems behave so differently?

There are many reasons, but perhaps the most significant is the nature of the crust in the two locations.

Hawaiʻi is located on oceanic crust, which is much thinner — about 6 miles thick — than the continental crust present at Yellowstone, which is about 28 miles thick. Because of the thinner crust underneath Hawai‘i, magma is able to rise more quickly and easily.

That means magma doesn’t have time to crystallize or interact with the crust and instead tends to erupt as runny, or low viscosity, basaltic lava flows. Eruptions also tend to be more frequent and smaller in volume.

In contrast, the thick continental crust underneath Yellowstone prevents magma from easily ascending. As a result, magma stalls and accumulates in the crust.

With time, this process has led to the development of a large magmatic system that spans most of the crust underneath Yellowstone and includes a large rhyolite magma reservoir in the upper crust — at depths of about 3 to 12 miles — that feeds Yellowstone’s dramatic eruptions.

Despite their outward differences, the fundamental engines that power volcanism in Yellowstone and Hawai‘i are quite similar.

So the next time you’re away from the islands and on the mainland, consider visiting the Yellowstone region. There’s a lot of aloha in southern Idaho and northwestern Wyoming.