Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/161967
Title: Estimating the velocity of pyroclastic density currents using an operational dual-PRF radar
Authors: Magfira Syarifuddin
Jenkins, Susanna F.
Taisne, Benoit
Oishi, Satoru
Ahmad Basuki
Iguchi, Masato
Keywords: Science::Geology
Issue Date: 2022
Source: Magfira Syarifuddin, Jenkins, S. F., Taisne, B., Oishi, S., Ahmad Basuki & Iguchi, M. (2022). Estimating the velocity of pyroclastic density currents using an operational dual-PRF radar. Journal of Volcanology and Geothermal Research, 424, 107462-. https://dx.doi.org/10.1016/j.jvolgeores.2021.107462
Journal: Journal of Volcanology and Geothermal Research 
Abstract: Pyroclastic density currents are one of the deadliest hazards produced by a volcano. Understanding their dynamics and generation mechanisms is critical for developing better hazard mitigation strategies. This study presents a method for retrieving velocity profiles across a natural moving PDC, applied here to a PDC generated by collapsing column during the eruption of Sinabung Volcano, Indonesia, on 19 February 2018 at the onset time of 08:53. We used an operational dual Pulse Repetition Frequency (PRF) weather radar, located ~7.8 km to the SE of the volcano, to estimate the velocity profile components of the volcanic plume: updraft, fallout, and horizontal advection. Doppler radar data was post-processed by applying two different filters: median and Laplacian, to correct errors associated with dealiased Doppler velocities. The Laplacian filter method was more effective in correcting the dealiasing errors by producing a more continuous velocity field without over smoothing its values. Following the dealiasing process, the velocity profile components were retrieved according to radar parameters such as Doppler velocities, copolar correlation, and reflectivity intensity factor. Initially, the pyroclastic clast was released at a lower exit velocity of ~120 m/s (84 s after the onset). A maximum of ~190 m/s exit velocity was then observed at 08:57:52 (292 s after onset). Lower exit velocity in the initial phase and less than 10 m/s estimated wind speed are the main factors causing the partial collapse of the plume at ~2.5 km height above the vent. The part of the collapsing column was associated with a more than 50 dBZ reflectivity intensity factor of fallout velocity exceeding −50 m/s at 126 s after the onset. Dilute PDCs were observed until 09:09:34 (994 s after onset), moving downslope at SE sector at a maximum velocity of −84 m/s (i.e., in the direction of the radar). The extracted velocity components are essential parameters in the numerical model of PDCs and tephra dispersal, enforcing the benefit of weather radar to complement the remote monitoring system of volcanic hazards.
URI: https://hdl.handle.net/10356/161967
ISSN: 0377-0273
DOI: 10.1016/j.jvolgeores.2021.107462
Rights: © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:ASE Journal Articles
EOS Journal Articles

Files in This Item:
File Description SizeFormat 
1-s2.0-S0377027321002912-main.pdf7.39 MBAdobe PDFThumbnail
View/Open

Page view(s)

29
Updated on Dec 2, 2022

Download(s)

4
Updated on Dec 2, 2022

Google ScholarTM

Check

Altmetric


Plumx

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.