Incorporating seismic observations into 2D conduit flow modeling

What makes a volcano tick—A first explanation of deep multiple seismic sources in ascending magma

“…Brittle failure of magma in a shear sense is now well documented (Gonnermann and Manga, 2003;Collier and Neuberg, 2006;Tuffen and Dingwell, 2005;Tuffen et al, 2008), and can be represented by the brittle failure criterion :…”

“…While several models explain the dominant LF characteristic of such events by resonance of a fl uid-fi lled conduit , dike or crack (Chouet, 1996), or more recently by magma "wagging" (i.e., oscillating; Jellinek and Bercovici, 2011), the actual source mechanism that starts the resonance is still controversial. Recent fi eld investigations (Tuffen and Dingwell, 2005), laboratory studies (Tuffen et al, 2008), and numerical models (Goto, 1999;Collier and Neuberg, 2006;Neuberg et al, 2006;De Angelis and Henton, 2011) have suggested rupture of magma as such a source mechanism; however, the existence of simultaneously active sources has not been explained. Two questions remain unanswered.…”

From magma ascent to ash generation: investigating volcanic conduit processes by integrating experiments, numerical modeling, and observations

“…For example, different techniques have estimated the dimension of the summit magma chamber at Kilauea from a fraction of to tens of cubic km. Another important point discussed by the group participants is the importance of taking into account 1D, 2D or 3D models, as we need to balance the computational expense versus the number of runs required to properly explore the parameter space and conduct a proper sensitivity analysis [Collier andNeuberg 2006, Longo et al 2012]. Other outstanding parameters/points discussed by numerical modelers to be considered in terms of modeling conduit processes are: closed versus open system degassing, lateral degassing, equilibrium and disequilibrium processes, conduit erosion and magma-water interaction, viscous heating, and heat loss effects [Macedonio et al 1994, Mangan et al 2004, Dufek and Bergantz 2005, Starostin et al 2005, Diller et al 2006, Costa et al 2007a, Degruyter et al 2010b, La Spina 2014.…”

Conditions for detection of ground deformation induced by conduit flow and evolution

“…Here, we are interested in the short timescale deformation occurring only during rapid changes in magma flow at shallow levels. In consequence, our model only focuses on the shallow part of a mature magmatic system associated with cylindrical shapes, which has already been considered in many studies in relationship with conduit flow [Wylie et al, 1999;Melnik and Sparks, 1999;Barmin et al, 2002;Collier and Neuberg, 2006;Lensky et al, 2008;Collombet, 2009].…”

“…St. Helens or Merapi, improvement of volcanic monitoring, with acquisitions of high-frequency and precise data, has permitted to identify cyclic patterns with a period of only a few hours, during phases of dome extrusion . Whereas cyclic deformation at long timescales is attributed to magma reservoir dynamics, short-timescale variations are explained by the nonlinear dynamics of magma flow in the volcanic conduit [Denlinger and Hoblitt, 1999;Voight et al, 1999;Wylie et al, 1999;Lensky et al, 2008;Collier and Neuberg, 2006]. Intermediate cycles with periods of several weeks have been attributed to the capacitor effect of dykes connecting magma reservoirs and upper conduits [Costa et al, 2007b].…”