Results 31 to 40 of about 5,469 (201)

Distal occurrence of mid-Holocene Whakatane Tephra on the Chatham Islands, New Zealand, and potential for cryptotephra studies [PDF]

, 2011
The Whakatane Tephra, a rhyolitic tephra erupted ca. 5500 cal. BP from Okataina Volcanic Centre, central North Island, has been identified on the Chatham Islands which lie ˜900 km east of Christchurch, New Zealand.
Hogg, Alan G., Holt, Katherine A., Lowe, David J., Wallace, R. Clel   +3 more
core   +2 more sources

Pyroclastic density currents

, 2013
This chapter summarizes the principal experimental and theoretical approaches used to investigate the physics of pyroclastic density currents (PDCs), which are gravity driven hot gas–particle mixtures commonly generated during explosive volcanic eruptions.
Roche, Olivier, Phillips, J.C., Kelfoun, Karim   +2 more
openaire   +2 more sources

Identifying Pyroclastic Density Currents From Partial Outcrop Exposure on Mt. Ruapehu, New Zealand

Frontiers in Earth Science, 2020
Pyroclastic density current (PDC) deposits, especially small to medium volume events, have low preservation potential at many volcanoes, particularly when unconsolidated or deposited on steep, glaciated slopes.
Janina K. Gillies, Ben M. Kennedy, Darren M. Gravley, Graham S. Leonard, James Cowlyn   +4 more
doaj   +1 more source

Spontaneous Unsteadiness and Sorting in Pyroclastic Density Currents and their Deposits [PDF]

, 2023
Pyroclastic density currents (PDCs) pose substantial risk to populations living on and around active volcanoes, but their structure and internal dynamics are poorly understood. Much of this understanding is derived from interpretation of their widespread deposits.
Pete Rowley, Rebecca Williams, Matthew Johnson, Thomas Johnston, Natasha Dowey, Daniel Parsons, Alison Provost, Olivier Roche, Gregory Smith, Nemi Walding   +9 more
openaire   +1 more source

IMEX_SfloW2D v2: a depth-averaged numerical flow model for volcanic gas–particle flows over complex topographies and water [PDF]

Geoscientific Model Development, 2023
We present developments to the physical model and the open-source numerical code IMEX_SfloW2D (de' Michieli Vitturi et al., 2019). These developments consist of a generalization of the depth-averaged (shallow-water) fluid equations to describe a ...
M. de' Michieli Vitturi, T. Esposti Ongaro, S. Engwell   +2 more
doaj   +1 more source

Scenario-Based Pyroclastic Density Current Invasion Maps at Poorly Known Volcanoes: A Case Study from Changbaishan (China/North Korea)

Applied Sciences, 2020
Changbaishan volcano (China/North Korea; last eruption in 1903 AD) was responsible for a Volcanic Explosivity Index (VEI) 7 eruption in 946 AD. Approximately 186,000 people live around Changbaishan and 2,000,000 tourists/year visit the volcano. An unrest
Anna Maria Lombardi, Pierdomenico Del Gaudio, Zhengfu Guo, Maoliang Zhang, Guoming Liu, Vincenzo Sepe, Jiaqi Liu, Guido Ventura   +7 more
doaj   +1 more source

Varying processes, similar results: How composition influences fragmentation and subsequent feeding of large pyroclastic density currents

Frontiers in Earth Science, 2022
Unlike their silicic counterparts, mafic eruptions are known for being on the low-end of the explosivity spectrum with eruption styles commonly ranging from effusive to Hawaiian fire fountaining.
Olivier Bernard, Olivier Bernard, Olivier Bernard, Caroline Bouvet de Maisonneuve, Caroline Bouvet de Maisonneuve, Laurent Arbaret, Laurent Arbaret, Kazuhide Nagashima, Jeffrey Oalmann, Arief Prabowo, Antonius Ratdomopurbo   +10 more
doaj   +1 more source

Dynamics of Pyroclastic Density Currents: Conditions That Promote Substrate Erosion and Self-Channelization - Mount St Helens, Washington (USA) [PDF]

, 2014
The May 18th, 1980 eruption of Mount St. Helens (MSH) produced multiple pyroclastic density currents (PDCs), burying the area north of the volcano under 10s of meters of deposits.
Bendaña, Sylvana, Brand, Brittany D., Dawson, Blaine, Mackaman-Lofland, Chelsea, Pollock, Nicholas M., Wichgers, Pamela   +5 more
core   +2 more sources

A Confidence-Based Assessment Method for Distinguishing Pyroclastic Density Current Deposits From Other Volcaniclastic Units

Frontiers in Earth Science, 2020
Pyroclastic density currents (PDCs) are a destructive volcanic hazard. Quantifying the types, frequency and magnitudes of PDC events is essential for effective risk management, but since historical records at best extend a few hundred years this usually ...
James Cowlyn, James Cowlyn, Ben M. Kennedy, Darren M. Gravley, Shane J. Cronin   +4 more
doaj   +1 more source

Holocene record of large explosive eruptions from Chaitén and Michinmahuida Volcanoes, Chile

Andean Geology, 2013
Tephra fall deposits and one large ignimbrite close to Chaitén and Michinmahuida Volcanoes were analyzed for chemistry and radiocarbon dated to correlate the eruptive units and establish the timing of eruptions.
Álvaro Amigo, Luis E. Lara, Victoria C. Smith   +2 more
doaj   +1 more source