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Our expert volcanologists and photographers offer unique travel experiences: volcano expeditions
, photo tours, and relaxed walking & study tours.
: spaces available / : guaranteed / : few spaces left / : booked out
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)
Volcanic tremor is a continuous seismic signal with regular or irregular sine wave appearance and low frequencies (0.5-5 Hz).
Volcanic tremor is usually in the form of harmonic tremor which has a very uniform appearance, whereas spasmodic tremor is pulsating and consists of higher frequencies with a more irregular appearance.
Tremor can be caused by different processes inside the volcano, including resonance triggered by magma flowing through cracks and vents, or continuous low-frequency earthquakes so closely spaced that they can't be visually separated, and explosions.
More on VolcanoDiscovery
Ambrym+Yasur volcanoes in Vanuatu
: An adventurous expedition to some of the most spectacular and active volcanoes in the world! Our volcano expedition to Vanuatu lets you spend 1 week on Ambrym with its multiple active lava lakes and 4 days on Yasur, famous for its spectacular fireworks. Guided by professional volcanologist, small groups (May-Sep).
Batu Tara photos
: A remote island in the Flores Sea of Indonesia formed by a single volcano that has been in strong strombolian eruption for years. We regularly lead expeditions to there where we camp several days to observe it.
Desert, Salt & Volcanoes
: Experience one of the geologically most active areas on the planet: the Danakil desert in northern Ethiopia. Highlights include Erta Ale volcano with its active lava lake and Dallol hydrothermal fields offering a surreal landscape of colors, salt, geysers and springs.