The response of two-phase hydrothermal systems to changing magmatic heat input at mid-ocean ridges
| dc.contributor.author | Choi, Jaewoon | en |
| dc.contributor.committeechair | Lowell, Robert P. | en |
| dc.contributor.committeemember | Hole, John A. | en |
| dc.contributor.committeemember | Gazel, Esteban | en |
| dc.contributor.department | Geosciences | en |
| dc.date.accessioned | 2014-10-17T06:00:28Z | en |
| dc.date.available | 2014-10-17T06:00:28Z | en |
| dc.date.issued | 2013-04-24 | en |
| dc.description.abstract | Hydrothermal processes at oceanic spreading centers are largely influenced by changing magmatic heat input. I use the FISHES code to investigate the evolution of surface temperature and salinity as a function of time-varying heat flux at the base of a two-phase, vapor-brine hydrothermal system. I consider a two-dimensional rectangular box that is 1.5 km deep and 4 km long with homogeneous permeability. Impermeable, insulated conditions are imposed on the left and right hand boundaries. To simulate time-varying heat flux from a sub-axial magma chamber of 500 m long half-width, I consider a variety of basal boundary conditions: (1) a constant heat flux with an value of 130 W/m2; (2) a sinusoidal heat flux with a period of 6 years and an amplitude ranging between 100 and 50 W/m2; (3) step, random, and exponential heat fluxes ranging between 200 and 15 W/m2; and (4) an analytical function of temporally decaying heat flux resulting from a simulated cooling, crystallizing magmatic sill. As a result of the investigation I find: (1) changes in bottom temperature and salinity closely follow the temporal variations in magmatic heat inputs; (2) the surface temperature response is severely damped and high frequency variations in heat flow are not detected; (3) in regions where phase separation of vapor and brine occurs, surface salinity variations may be recorded in response to changing conditions at depth, but these are smaller in amplitude. | en |
| dc.description.degree | Master of Science | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:616 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/50575 | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | hydrothermal system | en |
| dc.subject | two-phase flow | en |
| dc.subject | mid-ocean ridges | en |
| dc.subject | magmatic heat | en |
| dc.title | The response of two-phase hydrothermal systems to changing magmatic heat input at mid-ocean ridges | en |
| dc.type | Thesis | en |
| thesis.degree.discipline | Geosciences | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | Master of Science | en |
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