Areal distribution, thickness, mass, volume, and grain size of tephra-fall deposits from the 1992 eruptions of Crater Peak vent, Mt. Spurr Volcano, Alaska

2001 ◽  
Author(s):  
Robert G. McGimsey ◽  
Christina A. Neal ◽  
Colleen M. Riley
1992 ◽  
Vol 54 (8) ◽  
pp. 685-695 ◽  
Author(s):  
R S J Sparks ◽  
M I Bursik ◽  
G J Ablay ◽  
R M E Thomas ◽  
S N Carey

2020 ◽  
Vol 125 (6) ◽  
Author(s):  
Kazutaka Mannen ◽  
Toshiaki Hasenaka ◽  
Atsushi Higuchi ◽  
Koji Kiyosugi ◽  
Yasuo Miyabuchi

2005 ◽  
Vol 142 (2) ◽  
pp. 209-215 ◽  
Author(s):  
R. A. BATCHELOR

Tephra-fall deposits in the Late Mesoproterozoic Sleat Group (Torridonian) from Skye, Scotland, are described for the first time. Two individual beds occur within the Loch na Dal Formation which represents sedimentation in a shallow marine environment. Each bed has a distinctive brown, crumbly, amorphous appearance in the field and has sharp contacts with its host metasediment. This unique lithology is identical to that of albitic schists described recently from the Southern Highland Group, Dalradian Supergroup, which were identified as air-fall tuffs.


2021 ◽  
Vol 13 (24) ◽  
pp. 5174
Author(s):  
Magfira Syarifuddin ◽  
Susanna F. Jenkins ◽  
Ratih Indri Hapsari ◽  
Qingyuan Yang ◽  
Benoit Taisne ◽  
...  

Tephra plumes can cause a significant hazard for surrounding towns, infrastructure, and air traffic. The current work presents the use of a small and compact X-band multi-parameter (X-MP) radar for the remote tephra detection and tracking of two eruptive events at Merapi Volcano, Indonesia, in May and June 2018. Tephra detection was performed by analysing the multiple parameters of radar: copolar correlation and reflectivity intensity factor. These parameters were used to cancel unwanted clutter and retrieve tephra properties, which are grain size and concentration. Real-time spatial and temporal forecasting of tephra dispersal was performed by applying an advection scheme (nowcasting) in the manner of an ensemble prediction system (EPS). Cross-validation was performed using field-survey data, radar observations, and Himawari-8 imageries. The nowcasting model computed both the displacement and growth and decaying rate of the plume based on the temporal changes in two-dimensional movement and tephra concentration, respectively. Our results are in agreement with ground-based data, where the radar-based estimated grain size distribution falls within the range of in situ grain size. The uncertainty of real-time forecasted tephra plume depends on the initial condition, which affects the growth and decaying rate estimation. The EPS improves the predictability rate by reducing the number of missed and false forecasted events. Our findings and the method presented here are suitable for early warning of tephra fall hazard at the local scale.


2018 ◽  
Vol 80 (4) ◽  
Author(s):  
Masayuki Oishi ◽  
Kuniaki Nishiki ◽  
Nobuo Geshi ◽  
Ryuta Furukawa ◽  
Yoshihiro Ishizuka ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document