Escanaba Segment

Geography & Climate

Escanaba Segment is located in United States, within the Northeast Pacific Rifts Volcanic Province of the broader Eastern Pacific Volcanic Regions. Situated at 40.98° N, 127.50° W in the Northern Hemisphere, the volcano lies within a temperate climate zone. With an elevation of -1,700 meters — below sea level — Escanaba Segment is a submarine or submerged volcanic feature. Submarine volcanoes make up the majority of Earth's volcanic activity, though most eruptions go unobserved beneath the ocean surface. The volcanic landform is characterized as a cluster, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Escanaba Segment is situated along a rift zone, where tectonic plates are pulling apart. As the crust thins and fractures, magma rises to fill the gap, creating volcanic activity. Rift volcanism typically produces more fluid lava flows rather than explosive blasts, which means communities near Escanaba Segment in United States generally face slower-moving hazards like lava flows and ground fissures rather than sudden pyroclastic events. However, rift volcanoes can still generate significant ash emissions and gas releases that affect local air quality. The dominant rock type is basalt / picro-basalt, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Escanaba Segment has 1 recorded eruption in the geological database, spanning from 2260 BCE to 2260 BCE.

GVP Reference Summary

The linear, N-S-trending Escanaba Segment, the southernmost of the Gorda Ridge, lies immediately north of the Mendocino Francture Zone off the coast of northern California. The axial crest of the 130-km-long segment, also known as the Escanaba Trough, is about 3-5 km wide at the northern end and increases to 18 km to the south near the junction with the Mendocino FZ. The rift valley floor of the slow-spreading segment lies at about 3,200 m depth, bounded by faulted walls about 1,500 m high with unusual gold-bearing massive sulfide deposits in sediment hills at the base of the scarps uplifted by volcanic sills or lacoliths. Thick sediment deposits from the continental margin enter the axial trough from the fracture zone and thin to the north. A preliminary uranium-series date of Holocene age was obtained from a basaltic lava flow in the axial valley in the less-sedimented northern part.

— Smithsonian Institution, Global Volcanism Program