Illustrated Volcano Glossary

tephrite

Volcanology
Tephrite is an type of volcanic (extrusive) rock with low silica content, similar to basalt, but containing foid minerals (e.g. nephelinite, leucite) along with plagioclase.
The composition of tephrite is called tephritic.

tephritic

Volcanology
Tephritic refers to the mineral composition of tephrite, an type of volcanic (extrusive) rock with low silica content, similar to basalt, but containing foid minerals (e.g. nephelinite, leucite) along with plagioclase.

tremorSynonym of: volcanic tremor

Volcanology
Seismogram signal examples from volcanic earthquakes: Volcano Tectonic (VT) Low Frequency (LF), hybrid (mix of VT and LF), Very Low Frequency (VLF), and Tremor. Volcano name/date in lower left. (image: USGS)
Seismogram signal examples from volcanic earthquakes: Volcano Tectonic (VT) Low Frequency (LF), hybrid (mix of VT and LF), Very Low Frequency (VLF), and Tremor. Volcano name/date in lower left. (image: USGS)

tumulus

Volcanology
Tumulus with strange shapes, on the lava flow field of the 1614-24 eruption of Mt. Etna, Italy.
Tumulus with strange shapes, on the lava flow field of the 1614-24 eruption of Mt. Etna, Italy.
From Latin "tumulus" = "little hill", tumuli (pl.) are uplifted sections of pahoehoe lava crust caused by pressure from still fluid lava accumulating beneath the hardened crust.
Tumuli are a characteristic feature of all pahoehoe lava flow fields, such as prominent on Kilauea volcano, Hawaii, but also many other basaltic volcanoes including Etna. Read all
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