About Brothers
Brothers is a caldera rising to -1,350 meters (-4,429 feet) in New Zealand's Tonga-Kermadec Volcanic Regions. No historical eruptions have been recorded, though the volcano is classified based on geological evidence of past activity.
Geography & Climate
Brothers is located in New Zealand, within the Southern Kermadec Volcanic Arc of the broader Tonga-Kermadec Volcanic Regions. Situated at 34.88° S, 179.07° E in the Southern Hemisphere, the volcano lies within a subtropical climate zone. With an elevation of -1,350 meters — below sea level — Brothers 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 caldera, which describes the physical shape and structure of the volcanic edifice as observed from the surface.
Geological Context
Brothers sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in New Zealand near Brothers, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is dacite, an intermediate to silica-rich volcanic rock. This composition typically produces more viscous magma, leading to more explosive eruptions with ash columns and pyroclastic flows. Andesitic and dacitic magmas build pressure before erupting, which is why volcanoes with this rock chemistry are often associated with Plinian-style eruptions that can send ash tens of kilometers into the atmosphere and disrupt aviation across entire regions.
GVP Reference Summary
The submarine Brothers volcano, located NE of the Healy submarine volcano, contains an oval-shaped summit caldera 3-3.5 km elongated NW-SE. The high point of the dominantly dacitic edifice lies on the NW caldera rim at about 1,350 m below the ocean surface. The caldera floor is at about 1,850 m depth, and a post-caldera lava dome partially merges with the southern caldera wall. There is significant hydrothermal activity, including a large field of "black smoker" vents on the NW caldera wall and vents on the post-caldera dome.
— Smithsonian Institution, Global Volcanism Program
0 Recorded Eruptions
No eruption records available for Brothers.
Real-Time Data
USGS Alert Level
Thermal Anomalies
Frequently Asked Questions About Brothers
Is Brothers an active volcano?+
Brothers is not currently classified as active. Its activity evidence is listed as "Unrest / Holocene." No recorded eruptions have been documented. However, no volcano is ever considered permanently extinct.
How high is Brothers?+
Brothers has a summit elevation of -1,350 meters (-4,429 feet) above sea level. With an elevation of -1,350 meters (below sea level), this is a submarine or submerged volcanic feature.
What type of volcano is Brothers?+
Brothers is classified as a Caldera. Calderas are large volcanic depressions formed when a volcano erupts so powerfully that its magma chamber collapses, creating a basin that can be kilometers wide. They are often sites of some of Earth's largest eruptions.
Where is Brothers located?+
Brothers is located in New Zealand, in the Tonga-Kermadec Volcanic Regions. More specifically, it lies within the Southern Kermadec Volcanic Arc. Its exact coordinates are -34.875° latitude, 179.067° longitude.
Is it safe to visit Brothers?+
Brothers can generally be visited, but as with any volcano, visitors should check local conditions and any advisory notices before traveling. New Zealand may have specific regulations for accessing volcanic areas. Guided tours are often the safest and most informative way to experience a volcano.