FALL3D is a 3-D time-dependent Eulerian model for the transport and deposition of volcanic ashes and lapilli. The model solves the advection–diffusion–sedimentation (ADS) equation on a structured terrain-following grid using a second-order finite differences (FD) explicit scheme. Different parameterizations for the eddy diffusivity tensor and for the particle terminal settling velocities can be...

Recent seafloor exploration has shown that volcanic-hosted massive sulfides (VHMS) occur in modern silicic calderas formed by highly explosive eruptions at substantial water depths. Sampling of these has so far been restricted to surficial deposits. Ancient analogs provide a time-integrated view of the structure and fill of deepwater calderas, but constraints on paleo-water depths have previous...

Understanding the mechanisms that govern ash aggregation is of critical importance in volcanology. Aggregation reduces the residence time of ash (≤2 mm) in the atmosphere strongly, by enhancing the sedimentation of finer-grained material generated during explosive eruptions. To date, experimental studies have focused on the expectation that water provides the strongest bonds between particles t...

11 The Orapa Diamond Mine (Republic of Botswana) exposes a bi-lobate kimberlite 12 pipe that erupted during the Late-Cretaceous epoch (∼93 Ma) through Archaean 13 basement and volcano-sedimentary rocks of the Karoo Supergroup. Geological map14 ping of the crater zone of the South Pipe has revealed a 15–25 m thick in-situ 15 kimberlite pyroclastic flow deposit. The pyroclastic deposit fills in t...

Aggregation is a common process occurring in many diverse particulate gas mixtures (e.g. those derived from explosive volcanic eruptions, meteorite impact events, and fluid bed processing). It results from the collision and sticking of particles suspended in turbulent gas/air. To date, there is no generalized model of the underlying physical processes. Here, we investigate aggregates from 18 na...

Three voluminous rhyolitic ignimbrites have been identified along the southern margin of the central Snake River Plain. As a result of wide-scale correlations, new volume estimates can be made for these deposits: ~350 km for the Steer Basin Tuff and Cougar Point Tuff XI, and ~1,000 km for Cougar Point Tuff XIII. These volumes exclude any associated regional ashfalls and correlation across to th...

[1] Steam explosions, or littoral blasts, generated when pyroclastic flows interact with seawater may be a common, although rarely documented, phenomena. The development of steam explosions rather than passive steam production is related to the rate of thermal energy transfer from hot pyroclasts to water. We conduct a series of laboratory experiments to quantify the heat transfer and steam prod...

San Miguel (or Chaparrastique) volcano, El Salvador, erupted on the 29th December 2013, after almost 40 years of quiescence. Initial vent-clearing explosions ejected ballistic blocks and produced a pyroclastic density current (PDC) that flowed down upper flanks. Plume rise speeds peaked at 50–70 m s-1 declined over time. The main phase VEI 2 eruption Subplinian plume dispersed 106 m3 ash >20...

The effectiveness of chemical compounds for marking hard tissues in juvenile silver carp (Hypophthalmichthys molitrix) is not well known. We analyzed the use alizarin complexone (ALC) as a fluorescent marker to mark various structures carp. Experimental fish (~2 months old) were randomly assigned either control or groups, which immersed 0 100 mg/L ALC solutions, respectively, 2 days. otoliths, ...