15 slides = 3 min/slide + 15 min Qs Start with some philosophy of deep sea via interview: marine desert or oasis? 1) Title/outline 2) Motivation: Why measure hydrothermal heat flux? Photograph of HTV environment with plume(s), basalt/sulfides, and biology Whether sulfide hosted or otherwise, the advective flux of energy from crust to ocean is a fundamental characteristic of the system (environment + ecosystem). The main geological motivation is understanding more about how the oceanic crust forms, specifically by constraining the nature of the source of hydrothermal heating. Emplacement of large volumes of magma, in an axial "chamber" for example, will take a long time to cool, and therefore deliver a sea floor heat flux that changes little from year to year. A hydrothermal heat flux driven by a relatively low volume injection or eruption, like that associated with a dike, will decrease measurably on the time scale of a year. Most metabolic energy comes from chemical species carried in the the fluid. Chemical species also affect ocean chemistry, but to an extent that is determined by the volume flux (which conveniently falls out of the heat flux if you have some idea of the T of vents and their frequency distribution). 3) Background 1: Ok, so if you want to measure it, where and how shall it be done? Important to know what processes dominate in a study area... Schematic of generic CV and processes Show which process is dominant: Table of relative heat flux magnitudes for GENERIC htvf? T v #orA HF Advective: 0.05 10 10--100 High T: 350 100 100 150 Low T: 10 1 10%? 100 Diffusive? MW Conductive: 1 Radioactive: 1 Radiative: 10^-17 HF = rho cp T v A HF = -k dT/dx HF = I h c / lambda etc... Then choose methods that will lead to an accurate and precise characterization of the heat flux associated with the dominant process(es)... 4) Where? MEF geological map and ABE bathymetry MEF is well mapped, and focal point of past HF studies 5) How? The Flow Mow field program! Photos: ABE and CTD Graphic: Mooring map and CV with No/SoMEF/other station locs monitor v and T on all sides of a CV over MEF. HF = rho cp T v A, again, but as NET or heat budget eqn 4) Background 2: Study site ES map of fields with WA inset Op to interject new field locations -- update community! (He, H, CH4 vals?) 5) Background 3: Currents Consider the fate of a MEF-Mothra larvae. -- you're dispersed from a dying diffuse flow site, from parents just barely metabolically able -- Rectilinear M2 oscillations and northward mean flow take you northward -- Within the MEF, xx m from Dante you are entrained by flow of xx cm/s (likely just above 2185, mean source depth) -- Vertical velocity within the plume decreases rapidly, but gets you up 200\,m in about a half hour IF ADVECTION, THEN -- Multidirectional oscillations displace you ~km and mean flow of 5cm/s moves you southwestward -- some evidence that opposing mean flows on flanks would transport you along ridge... IF ROTATION (megaplume?), THEN -- ... -- How do you get back down? settle on particles?? swim? If sea breeze is right, then residence time in valley is ~1.6--8.1 days. ==> It is rare that Endeavour plumes rise into a stereotypically quiescent deep ocean! To locate sources or otherwise make sense of plume distributions, measurement of both the flow conditions and/or a non-conservative tracer is advisable. ** Talk is an op to present a bit of your ABE fly through analyses... (Look through web-dailylog to find a few "cool" plots? Explain main result figures: Mohamed bin-shaded? End with acknowledgments Readers: Russ -- availability, balance between advice and encouraged independence, teaching valuation, flexibility ... marriage, outdoor catalysis (looking forward to more!) Bill -- beyond call (and scope?!) of governmental duties Jeff -- early scaling help, particle curiosities Members, thank you for: Glenn -- On-going sounding board re currents and hydrography, editorial advice Susan -- Taught a geologist enough basic phys to survive; open with new data and ideas Will -- Opened eyes (forcibly?) to power of Matlab Steve -- Availability (despite changing schedules) and good questions MGG group, office mates: Fritz Christian Lisa Family/friends Annie Parents Sis/Peter Many wonderful others And finally: Announcement of my intent to continue applying science to deep sea exploration; excitement of funded Sea Breeze research But acknowledgment that we are now living in an era where science should also be applied directly to the urgent problems of human cooperation, resource struggles, and coincident environmental problem solving. oil field plume photograph