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Karen Thorne, USGS Western Ecological Research Center , Research Ecologist

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To assess the current topography of the tidal marshes we conducted survey-grade elevation surveys at all sites between 2009 and 2013 using a Leica RX1200 Real Time Kinematic (RTK)Global Positioning System (GPS) rover (±1 cm horizontal, ±2 cm vertical accuracy; Leica Geosystems Inc., Norcross, GA; Figure 4). At sites with RTK network coverage (San Pablo, Petaluma, Pt. Mugu, and Newport), rover positions were received in real time from the Leica Smartnet system via a CDMA modem (www.lecia-geosystems.com). At sites without network coverage (Humboldt, Bolinas, Morro and Tijuana), rover positions were received in real time from a Leica GS10 antenna base station via radio link. When using the base station, we adjusted...
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We performed bathymetric surveys using a shallow-water echo-sounding system (Takekawa et al., 2010, Brand et al., 2012) comprised of an acoustic profiler (Navisound 210; Reson, Inc., Slangerup, Denmark), Leica RTK GPS Viva rover, and laptop computer mounted on a shallow-draft, portable flat-bottom boat (Bass Hunter, Cabelas, Sidney, NE; Figure 7). The RTK GPS obtained high resolution elevations of the water surface (reported precision 10 cm water depth. We recorded twenty depth readings and one GPS location each second along transects spaced 100 m apart perpendicular to the nearby salt marsh. We calibrated the system before use with a bar-check plate and adjusted the sound velocity for salinity and temperature differences....
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We performed bathymetric surveys using a shallow-water echo-sounding system (Takekawa et al., 2010, Brand et al., 2012) comprised of an acoustic profiler (Navisound 210; Reson, Inc., Slangerup, Denmark), Leica RTK GPS Viva rover, and laptop computer mounted on a shallow-draft, portable flat-bottom boat (Bass Hunter, Cabelas, Sidney, NE; Figure 7). The RTK GPS obtained high resolution elevations of the water surface (reported precision 10 cm water depth. We recorded twenty depth readings and one GPS location each second along transects spaced 100 m apart perpendicular to the nearby salt marsh. We calibrated the system before use with a bar-check plate and adjusted the sound velocity for salinity and temperature differences....
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To assess the current topography of the tidal marshes we conducted survey-grade elevation surveys at all sites between 2009 and 2013 using a Leica RX1200 Real Time Kinematic (RTK)Global Positioning System (GPS) rover (±1 cm horizontal, ±2 cm vertical accuracy; Leica Geosystems Inc., Norcross, GA; Figure 4). At sites with RTK network coverage (San Pablo, Petaluma, Pt. Mugu, and Newport), rover positions were received in real time from the Leica Smartnet system via a CDMA modem (www.lecia-geosystems.com). At sites without network coverage (Humboldt, Bolinas, Morro and Tijuana), rover positions were received in real time from a Leica GS10 antenna base station via radio link. When using the base station, we adjusted...
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We used WARMER, a 1-D cohort model of wetland accretion (Swanson et al., 2014), which is based on Callaway et al. (1996), to examine the effects of three SLR projections on future habitat composition at each study site. Each cohort in the model represents the total organic and inorganic matter added to the soil column each year. WARMER calculates annual elevation changes relative to MSL based on projected changes in relative sea level, subsidence, inorganic sediment accumulation, aboveground and belowground organic matter inputs, soil compaction, and organic matter decomposition for a representative marsh area. Cohort density, a function of soil mineral, organic, and water content, is calculated at each time step...
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