Volcano Watch: Kamaʻehuakanaloa — The Volcano Formerly Known as Lōʻihi Seamount

Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates. This week’s article was written by Hawaiian Volcano Observatory geologist Natalia Deligne.

Kamaʻehuakanaloa volcano may seem unfamiliar, perhaps because its name was recently updated: in July 2021, Lōʻihi Seamount was renamed Kamaʻehuakanaloa by the Hawaii Board on Geographic Names.

The USGS Hawaiian Volcano Observatory (HVO) monitors 6 volcanoes: Kīlauea (currently erupting within Halemaʻumaʻu), Mauna Loa (most recent eruption in 1984), Hualālai (most recent eruption in 1801), Haleakalā (on Maui; most recent eruption sometime between 1480 to 1600 AD), Mauna Kea (most recent eruption over 4 thousand years ago), and Kamaʻehuakanaloa (most recent activity in 1996).

This last volcano may seem unfamiliar, perhaps because its name was recently updated: in July 2021, Lōʻihi Seamount was renamed Kamaʻehuakanaloa by the Hawaii Board on Geographic Names.

The former name was introduced in 1955 by Dr. Kenneth O. Emery, following a 4-day bathymetric (sea-floor topography) survey in 1954 off the south coast of the Island of Hawai’i. The survey was done at the request of the Office of Naval Research and five seamounts were identified.

Dr. Emery, a professor at the University of Southern California, asked Mary Kawena Pukui and Martha Hohu (both Bishop Museum staff), and Dr. Gordon A. Macdonald (HVO Director) to name the seamounts. They selected names based on a short physical description. For the seamount located about 30 miles (19 km) south of the Kīlauea coastline and rising to 3,189 ft (975 m) below sea level, the name Lōʻihi was assigned, meaning long; indeed, this seamount is longer than its neighbors.

At the time, Dr. Emery speculated that:

“There is a high degree of probability that the seamounts are of volcanic origin, and correspondingly that the differences which exist may be indications of the nature of the early stages of a volcano forming well below sea level. If this conclusion is correct then the two shallowest seamounts (Papa’u and Loihi) must be considered parasitic (in the sense of topography not activity) volcanoes on the flank of Kilauea…”

In other words, Dr. Emery interpreted “Loihi” to be a volcanic cone erupted by Kīlauea. However, the seamount was recognized to be an active submarine volcano, and the youngest volcano in the long line of the Hawaiian-Emperor chain, because of earthquake swarms in the 1970s. Kamaʻehuakanaloa’s most recent eruption is thought to have been in 1996, when HVO detected 4,377 earthquakes between mid-July and mid-August. Recent oceanographic surveys have also determined that Papa’u is an uplifted fault block on the margin of the Hilina slump, not a volcano.

Kamaʻehuakanaloa’s previous name was descriptive but failed to reflect Hawaiian cultural knowledge. Several mele (chants), orally passed down and documented in writing decades before the 1954 expedition, describe Kamaʻehuakanaloa, an undersea volcano. As explained by Kuʻulei Kanahele of the Edith Kanakaʻole Foundation, Kamaʻehuakanaloa “is a powerful name that invokes the name of Pelehonuamea and her birth out of Kanaloa [the ocean].” The new name was unanimously adopted in July 2021 by the Hawaiʻi Board on Geographic Names.

The recent violent explosive activity at Hunga Tonga-Hunga Ha’apai volcano, in the South Pacific, has some residents wondering if Kamaʻehuakanaloa has a potential for similar eruptions. We expect that as Hawaiian volcanoes near the surface and emerge, explosive interactions with ocean water may occur, but Kamaʻehuakanaloa is currently too deep underwater. Additionally, because Hawaiian volcanoes have more fluid magma than Hunga Tonga-Hunga Ha’apai, we expect smaller eruptions than the January 14, 2022, Hunga Tonga-Hunga Ha’apai catastrophic blast.

It will be a millennia before Kamaʻehuakanaloa emerges from Moananuiākea (the Pacific Ocean). The volcano does make its presence known with earthquakes that are occasionally felt on Island of Hawai’i, though.

Most recently, just before Christmas in the early morning of December 24th, 2021, a magnitude 4.9 earthquake under Kamaʻehuakanaloa caused weak to light shaking felt by at least 29 people from Nāʻālehu to as far north as Kailua Kona and Honomū. In the 2 weeks leading up to this earthquake, over 50 smaller earthquakes had been detected by HVO’s earthquake-monitoring network.

Kamaʻehuakanaloa may be out of sight, but it is not out of mind. It is honored in mele and though it remains under the ocean surface, it continues to occasionally remind us of its presence with earthquakes we can feel on land. In thousands of generations, perhaps our descendants will witness Kamaʻehuakanalo, the “reddish child of Kanaloa,” finally emerging and forming a new island.

Volcano Activity Updates

Kīlauea volcano is erupting. Its USGS Volcano Alert level is at WATCH (https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels). Kīlauea updates are issued daily.

Lava returned to the western vent within Halemaʻumaʻu crater at about 5:52 a.m. HST on January 25, following a pause lasting about two days. All lava is confined within Halemaʻumaʻu crater in Hawai‘i Volcanoes National Park. Sulfur dioxide emission rates remain elevated and were measured at approximately 2,800 tonnes per day on January 25. Seismicity is elevated but stable, with few earthquakes and ongoing volcanic tremor. Summit tiltmeters show several deflation and inflation patterns over the past week. For more information on the current eruption of Kīlauea, see https://www.usgs.gov/volcanoes/kilauea/recent-eruption.

Mauna Loa is not erupting and remains at Volcano Alert Level ADVISORY. This alert level does not mean that an eruption is imminent or that progression to an eruption from the current level of unrest is certain. Mauna Loa updates are issued weekly.

This past week, about 77 small-magnitude earthquakes were recorded below the summit and upper elevation flanks of Mauna Loa—the majority of these occurred at shallow depths less than 10 kilometers (6 miles) below sea level. Global Positioning System (GPS) measurements show low rates of ground deformation over the past week. Gas concentrations and fumarole temperatures at both the summit and at Sulphur Cone on the Southwest Rift Zone remain stable. Webcams show no changes to the landscape. For more information on current monitoring of Mauna Loa, see: https://www.usgs.gov/volcanoes/mauna-loa/monitoring.

Ten earthquakes were reported felt in the Hawaiian Islands during the past week. Listed here are felt events with magnitudes above 3: a M3.6 earthquake 8 km (4 mi) E of Pāhala at 34 km (21 mi) depth on Jan. 26 at 1:38 a.m. HST, a M4.7 earthquake 10 km (6 mi) NNE of Wailua at 41 km (25 mi) depth on Jan. 25 at 12:51 a.m. HST, and a M3.0 earthquake 9 km (5 mi) ENE of Pāhala at 32 km (20 mi) depth on Jan. 24, 2022 at 11:58 a.m. HST.

HVO continues to closely monitor Kīlauea’s ongoing eruption and Mauna Loa for any signs of increased activity.

Visit HVO’s website for past Volcano Watch articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake info, and more. Email questions to askHVO@usgs.gov.