Hiking the Naulu Trail to Makaopuhi: Hawaiʻi’s Explosive Crater Adventure. Volcano NP Hawaii USA p8

Hiking the Naulu Trail to Makaopuhi: Hawaiʻi’s Explosive Crater Adventure. Volcano NP Hawaii USA p8

Explosive phreatomagmatic crater: https://www.nps.gov/articles/000/phre...

🌦 Nāulu — Meaning

In Hawaiian, nāulu can mean:
A sudden rain shower or a localized cloudburst, often appearing unexpectedly.
Specifically, on the Kaʻū and Puna coasts of Hawaiʻi Island, a nāulu is a warm, moisture-laden cloud or rain shower that forms in the afternoons.
These nāulu clouds are famous in Hawaiian meteorology:
Trade winds push warm, moist air inland.
When this air rises along the heated lava plains near the coast, a short but intense rain shower can develop quickly.
This can happen even when the rest of the island is dry and sunny.

🥾 Nāulu Trail — Why It Has This Name

The Nāulu Trail in Hawaiʻi Volcanoes National Park was named for this characteristic weather phenomenon:
The trail crosses open lava fields that frequently experience nāulu cloudbursts in the afternoon.
Hikers may start in clear sunshine, only to be caught in a warm, fast-moving rain shower a couple of hours later.
These showers keep parts of the area greener and support pockets of ʻŌhiʻa rainforest inland.

🌺 Cultural Note

For Native Hawaiians, nāulu winds and rains were spiritually significant. Sudden rains were often associated with the presence of Hawaiian deities or ancestral spirits moving across the landscape. Names like Nāulu preserve this connection between language, weather, and place.

🌋 Makaopuhi Crater Eruption

Location: East Rift Zone of Kīlauea, Big Island, Hawaiʻi.
Type: Explosive phreatomagmatic crater (formed by interaction of magma and groundwater).

Formation / Eruption Period:
Makaopuhi Crater formed in approximately 600–700 AD, during a series of explosive eruptions.
These eruptions were phreatomagmatic, meaning magma interacted with water, causing violent steam-driven explosions.

Result:
The eruptions produced a large depression ~3 km long, with steep walls and a floor dotted with smaller collapse pits.
Surrounding area contains ash layers, tuff rings, and cinder cones.

Later Activity:
Since its initial formation, Makaopuhi has been dormant; no historical eruptions have occurred there in the modern era.
It is now a prominent scenic and geological feature along trails like the Nāulu Trail, giving hikers dramatic views of a volcanic crater formed hundreds of years ago.