TY  - JOUR
A1  - Reiss, Miriam Christina
A1  - Massimetti, Francesco
A1  - Laizer, Amani S.
A1  - Campus, Adele
A1  - Rümpker, Georg
A1  - Kazimoto, Emmanuel Owden
T1  - Overview of seismo-acoustic tremor at Oldoinyo Lengai, Tanzania: Shallow storage and eruptions of carbonatite melt
T2  - Journal of volcanology and geothermal research
N2  - Highlights
• We show the first observations of seismo-acoustic tremor at Oldoinyo Lengai, the world's only active carbonatite volcano.
• We observe significant changes in seismic and acoustic tremor properties and their correlation in one year of data collection.
• Using satellite-based thermal data, we identify different volcanic processes (degassing, lava pond dynamics and spattering).
Abstract
We analyze volcanic tremor from Oldoinyo Lengai, Tanzania, which is currently the only active volcano on Earth producing carbonatitic lavas. Here, we use data from the recent SEISVOL deployment and focus on a co-located seismic and infrasound station about 200 m below the summit. We show the very first observations of seismo-acoustic tremor caused by carbonatitic eruptions. This seismo-acoustic tremor is highly variable throughout the ∼one year of data which we characterize by analyzing its seismic amplitude, duration, recurrence, dominant seismic frequency and harmonics. Frequency gliding occurs frequently and over short (minutes to hours) to long time scales (hours to days) and likely reflects different time-dependent mechanisms, such as evenly-spaced repeating events with a change in inter-event times, crater dynamics that alter resonators, and dike intrusions. Seismic and acoustic wavefields correlate well for stronger eruptive sequences but are only partially coherent which suggests that high-frequency seismic tremor (up to 25 Hz) may be caused by the low viscosity of the carbonatitic melt and not by ground-coupled airwaves. In addition, the comparison between seismic-acoustic and satellite InfraRed thermal data allows us to infer different volcanic activity styles which partially alternate throughout the year: intrusive activity and the construction of hornitos, degassing, activity from a lava pond, and varying styles of extrusive activity, in particular spattering. Our study provides important insights into the eruption dynamics of this peculiar volcano which suggests shallow melt storage within the crater floor.
KW  - Seismo-acoustic tremor
KW  - Harmonic tremor
KW  - Open-vent volcano
KW  - Carbonatite eruptions
Y1  - 2023
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/79117
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-791179
SN  - 0377-0273
VL  - 442
IS  - 107898
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  -