Although both models provide plausible explanations for maar-diatreme growth, little quantitative work has explored the subsurface dynamics within diatremes. Many explosions that occur within a diatreme probably do not actually erupt (discharge material into the air), but remain confined in the diatreme. However, these “non-erupting” explosions possibly have an important role in both the upward transport of material in diatremes and may contribute to the overall mixing of the vent-filling debris, though the extent to which they NSC 146109 do remains unclear. While experiments (e.g. Ross et al., 2008a and Ross et al., 2008b; Andrews et al., 2014, Graettinger et al., 2014 and Valentine et al., 2015) have validated that discrete subsurface blasts can form subvertical deposits similar to those found in nature and inferred to be formed from debris jets, several outstanding issues pertaining to debris jets remain, particularly those related to processes occurring at natural length and time scales. Key problems relate to the dynamics of vertical transport and mixing of material within the subsurface environment, which is the focus of pelvic girdle paper. Specifically, we address the following outstanding questions in this work: (1) How far do debris jets travel in diatremes and how do the initial conditions (pressure, volume, depth) control these length scales? (2) From what depth(s), if any, are debris jets more likely to erupt? And (3) how is material redistributed in diatremes following an explosion?
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