Volcanology Brief Rangitoto Tectonic setting: Pacific Plate subducting beneath the Australian Plate; Auckland itself is an intraplate basaltic field. Why it matters: Auckland's youngest volcanic cone rises from the Hauraki Gulf and makes a perfect visual departure landmark.

Mount Tarawera Tectonic setting: Back-arc extension and subduction-related volcanism within the Taupō Volcanic Zone. Why it matters: The 1886 eruption ripped open a chain of craters across Tarawera; the fissure is still striking from the air.

Ruapehu Tectonic setting: Taupō Volcanic Arc in the east, transitioning west toward the isolated Taranaki volcanic centre. Why it matters: Ruapehu is New Zealand's highest active volcano and dominates the central North Island skyline.

Agung Tectonic setting: Sunda Arc volcanism generated by northward subduction of the Indo-Australian Plate. Why it matters: Agung is Bali's highest volcano and the island's dominant navigational landmark.

Semeru Tectonic setting: Sunda Arc subduction volcanism along densely populated eastern Java. Why it matters: Semeru is Java's highest volcano and forms the dramatic southern wall of the Tengger region.

Merapi Tectonic setting: Sunda Volcanic Arc, where rapid subduction feeds a closely spaced chain of active stratovolcanoes. Why it matters: Merapi is one of Indonesia's most persistently active volcanoes and sits immediately north of Yogyakarta.

Krakatau Tectonic setting: Sunda Arc subduction; the route crosses the volcanic spine of Java before reaching the Sunda Strait. Why it matters: The 1883 Krakatau eruption was one of the defining volcanic disasters of modern history; the caldera remains active.

Pinatubo Tectonic setting: Luzon volcanic arc and Philippine Mobile Belt, driven by complex subduction on both sides of the archipelago. Why it matters: Pinatubo's 1991 VEI-6 eruption formed the modern summit caldera and affected climate worldwide.

Mayon Tectonic setting: Luzon Volcanic Arc above subduction associated with the Philippine Mobile Belt. Why it matters: Mayon's near-symmetrical cone is one of the world's most recognisable stratovolcano profiles.

Sakurajima Tectonic setting: Ryukyu volcanic arc formed above subduction of the Philippine Sea Plate. Why it matters: Sakurajima sits inside Aira caldera beside Kagoshima and is one of Japan's most active volcanoes.

Fuji Tectonic setting: Complex junction of the Izu-Bonin, Northeast Japan and Nankai volcanic systems. Why it matters: Fuji is Japan's highest mountain and a young stratovolcano rising almost 12,400 ft above sea level.

Avachinsky Tectonic setting: Eastern Kamchatka volcanic arc above Pacific Plate subduction beneath the Okhotsk microplate. Why it matters: Avachinsky and Koryaksky form the dramatic twin-volcano backdrop to Petropavlovsk-Kamchatsky.

Klyuchevskoy Tectonic setting: Central and Eastern Kamchatka volcanic arcs above rapid Pacific Plate subduction. Why it matters: Klyuchevskoy is the towering centerpiece of Kamchatka's volcano group and among Eurasia's highest active volcanoes.

Shishaldin Tectonic setting: Aleutian volcanic arc formed by Pacific Plate subduction beneath the North American Plate. Why it matters: Shishaldin is a remarkably symmetrical cone rising from Unimak Island and makes an unmistakable VFR landmark.

Redoubt Tectonic setting: Alaska Peninsula volcanic arc above Pacific Plate subduction. Why it matters: Redoubt's eruptions have repeatedly affected aviation in Southcentral Alaska, making it a fitting aviation-volcanology waypoint.

Mount St Helens Tectonic setting: High Cascades volcanic arc above Juan de Fuca Plate subduction beneath North America. Why it matters: The 1980 eruption and sector collapse created the iconic breached crater visible from the air today.

Crater Lake / Mount Mazama Tectonic setting: High Cascades volcanic arc, continuing south from Oregon into northern California. Why it matters: Crater Lake occupies the collapse caldera of Mount Mazama, formed by a huge eruption roughly 7,700 years ago.

Popocatépetl Tectonic setting: Trans-Mexican Volcanic Belt related chiefly to subduction of the Cocos and Rivera plates. Why it matters: Popocatépetl is one of Mexico's most active volcanoes and rises immediately west of Puebla.

Fuego Tectonic setting: Central American volcanic arc above Cocos Plate subduction beneath the Caribbean Plate. Why it matters: Fuego is persistently active and sits beside the much larger Acatenango complex southwest of Guatemala City.

Cotopaxi Tectonic setting: Northern Andean volcanic arc above Nazca Plate subduction beneath South America. Why it matters: Cotopaxi is one of the world's highest active volcanoes and an extraordinary opening waypoint for the final stage.