(lower) The first published conceptual model of an idealized Hawaiian volcano as it appeared in the journal Science in 1960. (upper) A recent conceptual model of Kilauea volcano that is currently in review.

(Volcano Watch is a weekly article written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

A tradition each year on Valentine’s Day is the exchange of gifts. If you’re giving a gift you’ve wrapped, a big part of the fun is watching your true love receive the present. Most recipients look at how nicely the package is wrapped, give it a shake or two, and maybe even guess what they think might be inside before tearing the paper off. This ritual can be fun—but not always, if the person receiving the gift happens to be a volcanologist.

To some degree, volcanologists are puzzle-obsessed. Hand them a wrapped package on Valentine’s Day, and you might be there for hours as they measure its size and weight, feel its shape, sniff, shake, and listen to it, and maybe even check the historical records to determine if they’ve seen a gift that looked like this one in the past hundred years or so (You need to be careful about “re-gifting” to these folks).

If dedicated enough, your volcanologist valentine will do a final thing after gathering together the many pieces of data: start drawing a cartoon cross-sectional diagram of the inside of the gift on the back of an envelope. What you’ve just observed is a scientist (arguably one with a death wish) constructing a conceptual model to help solve the package puzzle.

The reason for this sort of puzzle obsession amongst volcano scientists is that many of them spend their lives trying to figure out what’s going on deep underground in places they will never actually get to see inside volcano “packages.”

Volcano conceptual models vary, but they typically appear as cartoon sketches of what we think the inside of the volcano might look like. By factoring in strategically different types of information, models help volcano researchers with diverse interests work together to formulate questions and devise experiments that test and refine the model’s validity.

Although the idea sounds simple, the first conceptual model for Hawaiian volcanoes wasn’t published until 1960. At that time, HVO scientists Jerry Eaton and Jack Murata were poring over data from newly modernized instruments, refined maps of surface vents and flows, and detailed analyses of the physical and chemical properties of Kilauea lavas. The result of their labors was a 3D representation of an idealized Hawaiian volcano’s sub-surface structure.

From the seismic and tilt data, Eaton and Murata’s diagram hypothesized that a relatively narrow conduit transports magma from a 60-km- (30-mi-) deep mantle source to shallow magma chambers from which lava can either be erupted at the summit or along rift zones. Their brave conceptual step forward was aided by the 1959 Kilauea Iki eruption at the summit, and the 1960 Kapoho eruption, on Kilauea’s lower east rift. Their paper, including the conceptual model, was published in the high profile journal Science. This fired up numerous researchers eager to apply their specialties—geophysics, geochemistry, geology and others—to test and extend the model.

The next significant enhancements to the conceptual model of Hawaiian volcanoes that we at HVO broadly use occurred after major expansions of Kilauea’s seismic and tilt networks, petrologic and gas studies, and geologic observational capabilities. Importantly, the enhanced computing power that became available to visualize and manipulate the data contributed to the model’s improvements. And once again, the model was driven forward by dramatic eruptive happenings, this time occurring both at Kilauea’s summit and east rift zone.

One scientific paper that will be part of a soon-to-be-released special volume commemorating HVO’s Centennial looks back at our progress toward better understanding of the nature of magma supply, storage, and transport at shield-stage Hawaiian volcanoes. Included in this paper is one of several late-breaking conceptual models for Kilauea. We’re looking forward to a widespread discussion in the volcano science community.

Solving volcano puzzles is not simply an intellectual pursuit; it is a practically applied one, as well. More than 500 million people worldwide live on or near active volcanoes. Understanding how volcanoes work helps us protect ourselves from their hazards while we appreciate their effusive beauty.