Scaling behavior and source mechanism of tremor recorded at Erebus volcano, Ross island, Antarctica

摘要: Abstract Erebus is an intraplate stratovolcano of phonolitic composition located at the southern end Terror Rift within West Antarctica system. The volcanic edifice exhibits a summit plateau that hosts main crater and smaller inner contains persistent lava lake. Volcano-seismic signals are recorded by permanent network short-period broadband seismometers installed around volcano edifice. We investigate duration-amplitude scaling tremor closest (~0.6–2 km) stations to during May 2002–April 2004 in order elucidate physical processes taking place its source. After screening data for related non-volcanic sources such as iceberg calving, we obtained 72 events. Spectral analysis reveals these events were either harmonic exhibiting several overtones or broadband, but there also mixed contained both two states. All episodes considered this study follow exponential distribution implies scale-bound source process. This precludes possibility any calving near Ross island, rock fracturing play role generation. large viscosity magma (~105.3 Pa s) suggests mechanisms which require high flow speeds excite unlikely operate Erebus. On other hand, oscillations CO2 bubble clouds formed localized asperities chamber represent consistent with observed oxidation state ascending gas deep (~5–7 km) location These results important understanding volcanoes which, similar Erebus, exhibit vigorous convection their shallow plumbing