In a place created entirely by molten lava, this year’s eruption on the Big Island reminds us that the volcanoes are in charge of our most hallowed race’s grounds.

In a place created entirely by molten lava, this year’s eruption on the Big Island reminds us that the volcanoes are in charge of our most hallowed race’s grounds.

In May of this year, news hit the mainland that the Kīlauea volcano on the eastern side of the Big Island had erupted. Signaled by a 5.0 earthquake on May 3, ground cracks opened in the small 1,500-person town of Leilani Estates, prompting evacuations. Over the next month, a series of earthquakes and lava flows destroyed roughly 700 homes, costing an estimated $800 million in recovery efforts, according to county officials’ estimates in a Sept. Honolulu Star Advertiser story.

Though the damage was terrible and the images and videos were gripping, the “lower Puna eruption”—named after the island’s district that was most affected—also reminded the mainland public that eruptions are nothing new on the island of Hawai’i. In fact, the lower Puna eruption isn’t technically considered to be a new eruption in some volcanologists’ circles—Kīlauea’s East Rift Zone has been in a near-constant state of eruption since 1983. In other words, that part of the Big Island has been going off since Dave Scott won his third Hawaii Ironman title and since the year this magazine was founded. Thirty-five years of triathlon and 35 years of lava.

With all of the actual destruction behind this year’s eruption, some triathletes had one thing in the back of their minds (admit it): Will the Ironman World Championship be affected? The quick answer was no. The eruption occurred on the east side of the Big Island and the race’s start and finish is on the western side—the bike runs up to the north, but still nowhere remotely near the damage. Kīlauea is actually the only one of the five major volcanoes that make up the land mass of the island of Hawai’i that doesn’t in some way intersect the IMWC course.

The course is so long that it cuts through four of the island of Hawai’i’s five volcano flow zones: Hualālai, Mauna Loa, Mauna Kea, and Kohala. The town of Kailua-Kona actually rests at the bottom of the Hualālai volcano—the airport that athletes fly into is built on a Hualālai lava flow from 1801. The same flow destroyed the nearby town of Kaʻūpūlehu, where resorts like the Four Seasons (and many Kona athletes) now rest today. Scientists at the Hawaii Center for Volcanology say that due to Hualālai’s steep slopes, a significant eruption and lava flow would likely overtake Ironman’s home base of Kailua-Kona in a number of hours (though it hasn’t erupted in 200 years).

Without overstating the facts, the Big Island literally wouldn’t exist if it weren’t for the living mountains that either lie dormant or periodically cause chaos. Like the rest of the Hawaiian islands, the Big Island of Hawai’i is formed from volcanoes. Though it is the biggest, Hawai’i is also the youngest of the Hawaiian islands chain—as such, it has Mauna Kea, the highest point in Hawaii. The dormant volcano’s peak rests at almost 14,000 feet; the boundaries of Mauna Kea’s lava flow extend from roughly mile 35 to mile 41 and from mile 79 to 85 on the IMWC bike course. This is a section near Waikoloa with a small plateau and short climb on the way out towards Hawi that is known for it’s precocious sidewinds.

The big volcanoes like Mauna Kea also provide for unusual weather patterns. Less than a week before this year’s race, temperatures on the top of Mauna Kea were a low of 23 degrees F; Kona had highs of 94 degrees F on the same day. It snowed up top at the same time it was nearly unbearable in the sun down below. As the bird flies, the distance between the summit of Mauna Kea and the IMWC finish line is just over 35 miles. The actual ride to the top (a favorite trek for non-racers) is more like 65 or 80 miles—depending on how you go.

And while the volcanoes may create tension in town and puzzling weather up top, the looming giants also affect the race down below. IMWC’s notorious crosswinds are due, in part, to the presence of endless, sweeping, moon-like lava fields out on the Queen K highway. But the volcanoes also quarantine the particularly nasty weather to the windward side of the Big Island. As much as people complain about the hot, humid, and windy conditions at IMWC, rain is essentially a non-factor: The month of October has historic averages of roughly half an inch of precipitation in Kona; Hilo, on the east side of Hawai’i has October averages just under 10 inches. These giant barriers both give and take.

As much as it’s the athletes who shape the Hawaii Ironman, it can sometimes be more of a race against the Big Island and its brutal and often violent environment. Though they may wreak havoc, these sleeping giants also play an essential role to the race and this place.

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