BEGIN:VCALENDAR VERSION:2.0 PRODID:-//18.83.4.138//NONSGML kigkonsult.se iCalcreator 2.20// CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Oceans at MIT X-WR-CALDESC:Striving to understand\, harness and sustain Earth'\;s def ining frontier. X-FROM-URL:http://oceans.mit.edu X-WR-TIMEZONE:America/New_York BEGIN:VTIMEZONE TZID:America/New_York X-LIC-LOCATION:America/New_York BEGIN:STANDARD DTSTART:20171105T020000 TZOFFSETFROM:-0400 TZOFFSETTO:-0500 RDATE:20181104T020000 TZNAME:EST END:STANDARD BEGIN:DAYLIGHT DTSTART:20180311T020000 TZOFFSETFROM:-0500 TZOFFSETTO:-0400 TZNAME:EDT END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT UID:20170421T100000-n91e8qdrst0dg1c0kqh59dudk0@google.com DTSTAMP:20180503T093131Z CATEGORIES;LANGUAGE=en-US:MIT Seminar | PAOC Chemical Oceanography and Biog eochemistry CONTACT: DESCRIPTION:The role of grain size on the seismic structure of the oceanic upper mantle and melt migration beneath midocean ridges\n\nGrain size is a key microstructural property of the Earth's mantle\, because it influence s rheology\, deformation mode (e.g.\, diffusion vs. dislocation creep)\, s eismic attenuation and wave-speeds\, electrical conductivity\, and the per meability of the mantle to melt migration. In\nthis talk I will discuss mo dels for grain size evolution in the oceanic upper that combine composite grain-size dependent rheology with the Wattmeter [Austin & Evans\, 2007] m odel for how grain size changes in response to the evolving deformation fi eld. These results will be interpreted in the context of the seismic low v elocity zone beneath the ocean basins and the origin of the lithosphere as thenosphere boundary. Finally\, I will discuss the implications of grain s ize variability on the patterns of melt migration beneath mid-ocean ridges and subduction zones and show the results of preliminary two-phase flow m odels that couple melt migration with the predicted grain-size field. DTSTART;TZID=America/New_York:20170421T100000 DTEND;TZID=America/New_York:20170421T110000 LOCATION:Building E25\, Room 119 SEQUENCE:0 SUMMARY:COG3 Seminar – Mark Behn (WHOI) URL:http://oceans.mit.edu/event/cog3-seminar-mark-behn-whoi X-ALT-DESC;FMTTYPE=text/html:\\n\\n\\n\\n\\nThe role of grai n size on the seismic structure of the oceanic upper mantle and melt migra tion beneath midocean ridges\n\nGrain size is a key microstructural proper ty of the Earth's mantle\, because it influences rheology\, deformation mo de (e.g.\, diffusion vs. dislocation creep)\, seismic attenuation and wave -speeds\, electrical conductivity\, and the permeability of the mantle to melt migration. In\nthis talk I will discuss models for grain size evoluti on in the oceanic upper that combine composite grain-size dependent rheolo gy with the Wattmeter [Austin & Evans\, 2007] model for how grain size cha nges in response to the evolving deformation field. These results will be interpreted in the context of the seismic low velocity zone beneath the oc ean basins and the origin of the lithosphere asthenosphere boundary. Final ly\, I will discuss the implications of grain size variability on the patt erns of melt migration beneath mid-ocean ridges and subduction zones and s how the results of preliminary two-phase flow models that couple melt migr ation with the predicted grain-size field. END:VEVENT END:VCALENDAR