Volcanoes / Lava Flows

Hawai'i Island has 5 volcanoes.  The park is on the slopes of Hualalai Volcano

Kaloko-Honokōhau has several volcanic flows inside its boundary, but these erupted long before Kaloko-Honokōhau became a park. The Hawaiian Islands are the tops of very large volcanic mountains formed on the floor of the Pacific Ocean. The islands are thought to have originated as the Pacific tectonic plate slowly moved over a relatively stationary hot spot in the underlying mantle. The Island of Hawaiʻi is formed from five separate subaerial shield volcanoes- Kohala, Mauna Kea, Hualālai, Kilauea, and Mauna Loa – and two submarine volcanoes, Loʻihi which is currently active, and Māhukona. Mauna Kea has been dormant for about the past 4,500 years and Kohala’s last eruption was around 60,000 years ago. The Earth’s largest active volcanic mountain, Mauna Loa, its tallest volcano from the base of the summit, Mauna Kea, and one of the world’s most active volcanoes, Kilauea reside on the Island of Hawaiʻi. The two primary types of lava flows in Hawaiian shield volcanoes are the smooth ropy pahoehoe and the rough angular ‘aʻa. Both types of lava are compositionally similar, and both can occur within the same flow. Kaloko-Honokōhau National Historical Park is underlain by lava flows that originated from Hualālai Volcano. Both pahoehoe and ‘a‘a flows are present in the park. Flows from three different ages are identifies in the park, and their periods of lava eruption, in years before present are 10,000 to 5,000 years before present (BP), 5,000 to 3,000 BP, and 3,000 to 1,500 BP. The most recent eruption of Hualālai, occurred in 1800-1801 and deposited lava 4km north of the park. These volcanic features can be seen along the Queen Kaʻahumanu Hwy or Route 19.

 

Eruption at Dawn at Halema'uma'u Crater on December 21, 2020

Photo by USGS

Eruption at Kilauea 12/20/2020. See Hawaii Volcanoes National Park for current info.
















WHAT ARE THE TWO MAIN TYPES OF LAVA?

Solidified pāhoehoe lava

Two types of lava flows can be seen in the park, pāhoehoe and ʻa‘ā.

Pāhoehoe lava appears smooth and ropy. It moves slower and stays hotter than ʻaʻā lava. When flowing, it can form lava tubes and may have many flow units known as "toes" because it is more runny and less viscous.

Solidified ʻa‘ā lava

ʻA‘ā lava, by contrast, appears rough, jagged, and chunky. It moves fast, with high velocity, and loses heat quickly while flowing. ʻA‘ā lava is much more viscous than pāhoehoe and flows in fewer, larger channels.

Most flows consist of both pāhoehoe and ‘a‘ā at various points, though the proportion of each can vary widely. Pāhoehoe upstream often changes to ‘a‘ā downstream. Although it is possible, ‘a‘ā flows transition into pāhoehoe less often.

 

All About LAVA.....

Lava or Magma?

Magma and lava are the same substance, but in different places. The term magma refers to molten rock that is still within the earth. Once it breaks through the earth's surface, it is referred to as lava.
 

How HOT is Hot Lava?

The temperature of erupting lava from Kīlauea is about 2,100 degrees Fahrenheit (1,150 degrees Celsius). Erupting lava cools quickly when it is exposed to air, hundreds of degrees per second, though rocks may steam for years after an eruption.
 

Why Don't Hawaiian Volcanoes Explode As Violently As Others?

Although powerful, Hawaiian volcanic eruptions are famous for being relatively benign and approachable, in comparison with volcanoes elsewhere. Hawaiian eruptions are not nearly as explosive as those like Mount St. Helens in 1980. The reason for this lies in the chemical composition of the magma that feeds these volcanoes.

Hawaiian magma contains comparatively little silica and is highly fluid. Accordingly, it can flow relatively freely and release gas easily. On the other hand, the magma of volcanoes located along the edges of tectonic plates, such as Mount St. Helens, has a different composition that makes it much more viscous (less fluid). It tends hold more gas and break apart, possibly explosively, during eruptions.

The easy flowing, fluid nature of lava from Hawaiian volcanoes contributes to their shape and is why they are referred to as shield volcanoes. Lava easily flows down the sides of the volcano, giving it a rounded appearance like a Roman warrior's shield.

 

Graphic courtesy of USGS Hawaiian Volcano Observatory

 

What Does Lava Sound Like?

An episode of the Voices of Science podcast from the National Park Service explores lava and features sounds of the 2008-2018 summit lava lake and flows from Puʻu ʻŌʻō.
 
 

 

A simplified cross-section of Hawaiʻi Island and the Hawaiian hot spot (NPS Graphic)

NPS

Volcanoes

Volcanoes are monuments to Earth's origins, evidence that its primordial forces are still at work. Over time, these prodigious land builders have created the Hawaiian island chain itself. Kīlauea and Mauna Loa are still adding to the island of Hawaiʻi and put this incredible phenomenon on full display.

 

Why Are Volcanoes Here?

The eight Hawaiian Islands we know today are only the most recent formations in a chain of over 80 volcanoes that stretch for thousands of miles to the northwest, both above and below sea-level. The further southeast in this chain, the younger the volcano, ending with the island of Hawai’i and Lō‘ihi, a growing volcano still beneath the ocean’s surface.

All of the volcanoes (both active and inactive) in this long chain formed because of the Hawaiian hot spot, a stationary plume of super-heated material deep in the earth. Heat from this material rises, eventually melting rock into magma. The magma then continues to rise. When some of it pushes its way to the surface, a volcanic eruption takes place.

The exact size of the Hawaiian hot spot is not fully understood, but it is large enough to encompass most of the Island of Hawaiʻi. Some scientists estimate the hot spot to be about 200 miles across, with much narrower vertical passageways that feed magma to the individual volcanoes.

Meanwhile, the Pacific Plate, one of the several tectonic plates that move around the surface of the earth, migrates slowly to the northwest. As it moves an estimated 2-4 inches per year, it carries with it any land that formed during volcanic eruptions.

The result is like an assembly line. The hotspot stays in one place, producing new land through eruptions, and the pacific plate carries them away. The geological formation of the Hawaiian Islands through this process mirrors the legendary journey of the Hawaiian volcano deity Pele to the island of Hawaiʻi.

Eventually, the Island of Hawai’i too will be moved by the tectonic plate away from the hotspot. It will follow in the footsteps of the older Hawaiian Islands to the northwest, and volcanic activity on the island will cease. New volcanic islands, still unborn, will come up behind it.

 

Hualālai on the Westside of Hawaiʻi Island  CLICK on picture for Video view from the park!

USGS photo
NPS video by Emi Harase

Island of Giants

Lapakū i Hawaiʻi ka wahine, aʻo Pele
(Pele is most active on Hawaiʻi Island)
Although Kīlauea and Mauna Loa are by far the most active, they combine with three other volcanoes to make up the Island of Hawaiʻi. Mauna Kea, Hualālai, and the Kohala Mts.

These three volcanoes are much older and less likely to erupt than their younger siblings to the south. However, Hualālai, upon which Kailua-Kona is built, last erupted in only 1801. It is still considered active. Mauna Kea, which last erupted an estimated 4,500 years ago, is also likely to erupt again, although its periods of quiet are much longer. Kohala, the oldest volcano on the island, has concluded its period of eruptive activity.