Results 71 to 80 of about 1,522 (205)

Experimental constraints on volcanic ash generation and clast morphometrics in pyroclastic density currents and granular flows

Volcanica, 2020
Pyroclastic density currents (PDCs) are a prominent hazard of volcanic activity; however, fully quantitative observations are lacking and little direct evidence exists to constrain the parameters controlling ash production and runout. Here, we use rotary
Adrian Hornby, U Kueppers, Benedikt Maurer, Carina Poetsch, Donald Dingwell   +4 more
doaj   +1 more source

Tracking a Rangeland Fire With Infrasound Arrays

Geophysical Research Letters, Volume 53, Issue 13, 16 July 2026.
Abstract We present the first infrasound analyses of a rangeland fire and demonstrate infrasound's potential in monitoring wildland fires. We recorded a prescribed fire in sagebrush steppe in cool, moist conditions, using eight infrasound arrays of diverse size (3–44 sensors, 10–200 m width) and distance (0–20 km), including four arrays inside the burn
Jacob F. Anderson, Madeline A. Hunt, Jeffrey B. Johnson, Kara M. Yedinak   +3 more
wiley   +1 more source

Trigger mechanism and propagation dynamics of pyroclastic density currents at basaltic volcanoes

Communications Earth & Environment
Pyroclastic density currents (PDCs) are among the deadliest manifestations of volcanic eruptions, commonly associated with volcanoes characterized by intermediate to felsic magma compositions and related to eruption column collapse, lateral blasts, or ...
Francesco Zuccarello, Daniele Andronico, Paola Del Carlo, Mattia de’ Michieli Vitturi, Alessio Di Roberto, Gaetana Ganci, Boris Behncke, Tomaso Esposti Ongaro, Francesco Ciancitto, Annalisa Cappello   +9 more
doaj   +1 more source

Dynamics of pyroclastic density currents and submarine eruptions [PDF]

, 2017
Density gradients are fundamental drivers of volcanic flows. Pyroclastic density currents propagate because they are more dense than the ambient fluid and pyroclasts can rise through water as a result of their buoyancy.
Fauria, Kristen
core  

Loess Studies in Aotearoa New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Loess in Aotearoa New Zealand (ANZ) has been studied since its first documented recognition (on Banks Peninsula) in 1878 by Julius von Haast. A decade later, John Hardcastle revealed that southern ANZ loess was both glacial in origin and contained signals of past climates.
Brent V. Alloway, David J. Lowe, Bradley J. Pillans, Peter C. Almond, Alan S. Palmer   +4 more
wiley   +1 more source

An Overview of Tsunami Hazards in the Southwest Pacific Ocean

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
The southwest Pacific region is geologically complex and exhibits all the principal causes of tsunami generation. While contemporary events and historical catalogs indicate that trans‐Pacific tsunamis have affected this area (∼18% of tsunamis reported globally), it is unique in that a large part of the tsunami effects over the ∼200‐year historical ...
Jean H. M. Roger, Bruce E. O. Thomas, Jose Borrero, Brook Tozer, Julien Collot, Samuel Etienne, Catherine Chagué, Patrick D. Nunn, Emily M. Lane, Shaun Williams, David Burbidge, Hannah E. Power, William Power, Bernard Pelletier   +13 more
wiley   +1 more source

Progressively Fenitised Schist and Carbonatitic Clasts From a Metasomatic Aureole Beneath the Alkalic Dunedin Volcano, Otago, New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Clasts of albite‐porphyroblastic quartzofeldspathic schist, derived from the Otago Schist basement, occur within the Port Chalmers Breccia, a diatreme at the centre of the Dunedin stratovolcano, New Zealand. Schists have undergone varying degrees of replacement reactions (at temperatures of 300° to >500°C) producing hornfelses, with Ca‐ and K‐enriched ...
Alan F. Cooper
wiley   +1 more source

CHAPTER 4.4 Pyroclastic Density Currents

Pyroclastic density currents (PDCs) are hot mixtures of gases and volcanic rock of diverse size, nature, or density, capable of flowing over long distances at velocities of tens to hundreds of kilometers per hour. They typically originate from the gravitational collapse of explosive eruption columns, lava domes or lava-flow fronts, unstable upper-flank
Sylvain Charbonnier, Eric Breard, Samantha Engwell, Olivier Roche, Walter Baez, Marina Belousova, Briitany Brand, Geoffrey Lerner, Sarah Ogburn   +8 more
openaire   +1 more source

Vertical and Spatial Geochemical Variations of Nishinoshima Volcaniclastic Deposits, Japan, During Episode 4

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Nishinoshima is a volcanic island in the Ogasawara Arc that has exhibited intermittent activity since 2013, including four major eruptive episodes: 2013–2015 (Episode 1), 2017 (Episode 2), 2018 (Episode 3), and 2019–2020 (Episode 4). Previous studies reported a change in eruption style—from a Strombolian eruption with lava flows (Episode 1 to the early
Erika Tanaka, Kenta Yoshida, Tomoki Sato, Yoshiro Nishio, Yoshihiko Tamura   +4 more
wiley   +1 more source

The fluidization behaviour of ignimbrite at high temperature and with mechanical agitation

, 2004
Experiments were carried out to study the fluidization behaviour of ignimbrite at high temperature and while being mechanically agitated. Geldart group C behaviour occurs up to 565 degreesC when the material is subjected to increasing gas flow ( without ...
Druitt, TH, Lettieri, P, Bruni, G, Yates, JG   +3 more
core