Woods Hole Coastal and Marine Science Center
Publications by year, USGS Woods Hole Coastal and Marine Science Center
All Publications by WHCMSC Authors for the year 2013
Ackerman, S.D., Andrews, B.D., Foster, D.S., Baldwin, W.E., and Schwab, W.C., 2013, High-Resolution Geophysical Data from the Inner Continental Shelf: Buzzards Bay, Massachusetts:
U.S. Geological Survey Open-File Report 2012-1002
. Online at http://pubs.usgs.gov/of/2012/1002/
Andrews, B.D., Ackerman, S.D., Baldwin, W.E., Foster, D.S., and Schwab, W.C., 2013, High-Resolution Geological Mapping of the Inner Continental Shelf: Vineyard Sound, Massachusetts.:
U. S. Geological Survey, Open-File Report 2012-1006
. Online at http://pubs.usgs.gov/of/2012/1006/
The U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM) have mapped approximately 340 square kilometers of the inner continental shelf in Vineyard Sound, Massachusetts, under a cooperative mapping program. The geophysical data collected between 2009 and 2011 by the U.S. Geological Survey as part of this program are published in this report. The data include (1) swath bathymetry from interferometric sonar, (2) acoustic backscatter from sidescan sonar, and (3) seismic-reflection profiles from a chirp subbottom profiler. These data were collected to support research on the influence of sea-level change and sediment supply on coastal evolution and sediment transport processes and to provide baseline seabed characterization information required for management of coastal and offshore resources within the coastal zone of Massachusetts.
Andrews, B.D., Chaytor, J.D., Brothers, D.S., and ten Brink, U.S., 2013, Bathymetric Terrain Model of the Atlantic Margin for Marine Geological Investigations.:
U.S. Geological Survey Open-File Report 2012-1266
. Online at http://dx.doi.org/10.3133/ofr20121266
Armstrong, B.N., Warner, J.C., List, J.H., Thieler, E.R., Martini, M.A., Voulgaris, G., McNinch, J., Book, J.W., Haas, K., and Montgomery, E., 2013, Carolinas Coastal Change Processes Project Data Report for nearshore observations at Cape Hatteras, North Carolina, February, 2010:
U.S. Geological Survey Open-File Report 2012-1219
. Online at http://pubs.usgs.gov/of/2012/1219
Brothers, D.S., ten Brink, U.S., Andrews, B.D., Chaytor, J.D, and Twichell, D, 2013, Geomorphic Process Fingerprints in Submarine Canyons:
, v. 337
, pp. 53-66
Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment fromthe continents to the deep sea. Though it is known that submarine canyons formprimarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based
expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scalemorphology of 171 slope-sourced canyons. Loglog regression
analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal
profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a
predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics
Brothers, D.S., ten Brink, U.S., Andrews,B.D., Chaytor, J.D.,, 2013, Geomorphic characterization of the U.S. Atlantic continental margin:
, v. 338
, pp. 46-63
The increasing volume of multibeam bathymetry data collected along continentalmargins is providing new opportunities
to study the feedbacks between sedimentary and oceanographic processes and seafloormorphology.
Attempts to develop simple guidelines that describe the relationships between form and process often overlook
the importance of inherited physiography in slope depositional systems. Here, we use multibeam bathymetry
data and seismic reflection profiles spanning the U.S. Atlantic outer continental shelf, slope and rise from Cape
Hatteras to New England to quantify the broad-scale, across-margin morphological variation. Morphometric
analyses suggest the margin can be divided into four basic categories that roughly align with Quaternary sedimentary
provinces.Within each category, Quaternary sedimentary processes exerted heavy modification of submarine
canyons, landslide complexes and the broad-scalemorphology of the continental rise, but they appear to
have preservedmuch of the pre-Quaternary, across-margin shape of the continental slope.Without detailed constraints
on the substrate structure, first-order morphological categorization the U.S. Atlantic margin does not
provide a reliable framework for predicting relationships between form and process.
Brothers, L.L., Van Dover, C.L., German, C.R., Kaiser, C.L., and Yoerger, D.R., 2013, Re-examination of seep activity at the Blake Ridge Diapir:
Fire in the Ice, DOE Newsletter
Brothers, L.L., Van Dover, C.L., German, C.R., Kaiser, C.L., Yoerger, D.R., Ruppel, C.D., Lobecker, E., Skarke, A.D., and Wagner, J.K.S, 2013, Evidence for extensive methane venting on the southeastern U.S. Atlantic margin:
. Online at 10.1130/G34217.1
We present the first evidence for widespread seabed methane venting along the southeastern United States Atlantic margin beyond the well-known Blake Ridge diapir seep. Recent ship- and autonomous underwater vehicle (AUV)collected data resolve multiple water-column anomalies (>1000 m height) and extensive new chemosynthetic seep communities at the Blake Ridge and Cape Fear diapirs. These results indicate that multiple, highly localized fluid conduits punctuate the areally extensive Blake Ridge gas hydrate province, and enable the delivery of significant amounts of methane to the water column. Thus, there appears to be an abundance of seabed fluid flux not previously ascribed to the Atlantic margin of the United States.
Butman, B., Aretxabaleta,A., Dickhudt, P., Dalyander, P.S., Sherwood, C.R., Anderson, D.M., Keafer, B.A., and Signell, R.A., 2013, Investigating the importance of sediment resuspension in Alexandrium fundyense cyst population dynamics in the Gulf of Maine:
Deep Sea Research II
. Online at 10.1016/j.dsr2.2013.10.011
Cysts of Alexandrium fundyense, a dinoflagellate that causes toxic algal blooms in the Gulf of Maine, spend the winter as dormant cells in the upper layer of bottom sediment or the bottom nepheloid layer and germinate in spring to initiate new blooms. Erosion measurements were made on sediment cores collected at seven stations in the Gulf of Maine in the autumn of 2011 to explore if resuspension (by waves and currents) could change the distribution of over-wintering cysts from patterns observed in the previous autumn; or if resuspension could contribute cysts to the water column during spring when cysts are viable. The mass of sediment eroded from the core surface at 0.4 Pa ranged from 0.05 kg m−2 near Grand Manan Island, to 0.35 kg m−2 in northern Wilkinson Basin. The depth of sediment eroded ranged from about 0.05 mm at a station with sandy sediment at 70 m water depth on the western Maine shelf, to about 1.2 mm in clayeysilt sediment at 250 m water depth in northern Wilkinson Basin. The sediment erodibility measurements were used in a sediment-transport model forced with modeled waves and currents for the period October 1, 2010 to May 31, 2011 to predict resuspension and bed erosion. The simulated spatial distribution and variation of bottom shear stress was controlled by the strength of the semi-diurnal tidal currents, which decrease from east to west along the Maine coast, and oscillatory wave-induced currents, which are strongest in shallow water. Simulations showed occasional sediment resuspension along the central and western Maine coast associated with storms, steady resuspension on the eastern Maine shelf and in the Bay of Fundy associated with tidal currents, no resuspension in northern Wilkinson Basin, and very small resuspension in western Jordan Basin. The sediment response in the model depended primarily on the profile of sediment erodibility, strength and time history of bottom stress, consolidation time scale, and the current in the water column. Based on analysis of wave data from offshore buoys from 1996 to 2012, the number of wave events inducing a bottom shear stress large enough to resuspend sediment at 80 m ranged from 0 to 2 in spring (April and May) and 0 to 10 in winter (October through March). Wave-induced resuspension is unlikely in water greater than about 100 m deep. The observations and model results suggest that a millimeter or so of sediment and associated cysts may be mobilized in both winter and spring, and that the frequency of resuspension will vary interannually. Depending on cyst concentration in the sediment and the vertical distribution in the water column, these events could result in a concentration in the water column of at least 104 cysts m−3. In some years, resuspension events could episodically introduce cysts into the water column in spring, where germination is likely to be facilitated at the time of bloom formation. An assessment of the quantitative effects of cyst resuspension on bloom dynamics in any particular year requires more detailed investigation.
Cross, V.A., Bratton, J.F., Kroeger, K.D., Crusius, J., and Worley, C.W., 2013, Continuous Resistivity Profiling Data from Great South Bay, Long Island, New York:
U.S.Geological Survey Open-File Report 2011-1040
. Online at http://pubs.usgs.gov/of/2011/1040
Dalyander, P.S., Butman, B., Sherwood, C., Signell, R., and Wilkin, J, 2013, Characterizing Wave- and Current- Induced Bottom Shear Stress: U.S. Middle Atlantic Continental Shelf:
Continental Shelf Research
, v. 52
, pp. 73-86
Waves and currents create bottom shear stress, a force at the seabed that influences sediment texture distribution, micro-topography, habitat, and anthropogenic use. This paper presents a methodology for assessing the magnitude, variability, and driving mechanisms of bottom stress and resultant sediment mobility on regional scales using numerical model output. The analysis was applied to the Middle Atlantic Bight (MAB), off the U.S. East Coast, and identified a tidally-dominated shallow region with relatively high stress southeast of Massachusetts over Nantucket Shoals, where sediment mobility thresholds are exceeded over 50% of the time; a coastal band extending offshore to about 30 m water depth dominated by waves, where mobility occurs more than 20% of the time; and a quiescent low stress region southeast of Long Island, approximately coincident with an area of fine-grained sediments called the Mud Patch. The regional high in stress and mobility over Nantucket Shoals supports the hypothesis that fine grain sediment winnowed away in this region maintains the fine-grained Mud Patch to the southwest. The analysis identified waves as the driving mechanism for stress throughout most of the MAB, excluding Nantucket Shoals and sheltered coastal bays where tides dominate; however, the relative dominance of low-frequency events varied regionally, and increased southward toward Cape Hatteras. The correlation between wave stress and local wind stress was lowest in the central MAB, indicating a relatively high contribution of swell to bottom stress in this area, rather than locally generated waves. Accurate prediction of the wave energy spectrum was critical to produce good estimates of bottom shear stress, which was sensitive to energy in the long period waves.
Denny, J.F., Schwab, W.C., Baldwin, W.E., Barnhardt, W.A., Gayes, P.T., Morton, R.A., Warner, J.C., Driscoll, N.W., and Voulgaris, G, 2013, Holocene Sediment Distribution on the Long Bay Inner Continental Shelf, between Little River Inlet to Winyah Bay: Implications to the Regional Sediment Budget and Shoreline Response:
Journal of Coastal Research
High-resolution geophysical and sediment sampling surveys were conducted offshore of the Grand Strand, South Carolina to define the shallow geologic framework of the inner shelf. Results are used to identify and map Holocene sediment deposits, infer sediment transport pathways, and discuss implications for the regional coastal sediment budget.
The thickest deposits of Holocene sediment observed on the inner shelf form shoal complexes composed of moderately sorted fine sand, which are primarily located offshore of modern tidal inlets. These shoal deposits contain ~67 M m3 of sediment, approximately 96% of Holocene sediment stored on the inner shelf. Due to the lack of any significant modern fluvial input of sand to the region, the Holocene deposits are likely derived from reworking of relict Pleistocene and older inner-shelf deposits during the Holocene marine transgression. The Holocene sediments are concentrated in the southern part of the study area, due to a combination of ancestral drainage patterns, a regional shift in sediment supply from the northeast to the southwest in the late Pleistocene, and proximity to modern inlet systems. Where sediment is limited, only small, low relief ridges have formed and Pleistocene and older deposits are exposed on the seafloor. The low-relief ridges are likely the result of a thin, mobile veneer of sediment being transported across an irregular, erosional surface formed during the last transgression.
Sediment textural trends and seafloor morphology indicate a long-term net transport of sediment to the southwest. This is supported by oceanographic studies that suggest the long-term sediment transport direction is controlled by the frequency and intensity of storms that pass through the region, where low pressure systems yield net along-shore flow to the southwest and a weak onshore component.
Current sediment budget estimates for the Grand Strand yield a deficit for the region. Volume calculations of Holocene deposits on the inner shelf suggest that there is sufficient sediment to balance the sediment budget and provide a source of sediment to the shoreline. Although the processes controlling cross-shelf sediment transport are not fully understood, in sediment-limited environments such as the Grand Strand, erosion of the inner shelf likely contributes significant sediment to the beach system.
Guida, Vincent G., Valentine, Page C., and Gallea, Leslie, B., 2013, Water temperature changes in seabed habitats of the northern margin of Georges Bank caused by movement of the semidiurnal tidal front in the warm season and possible ecological implications:
Continental Shelf Research
. Online at 10.1371/journal.pone.0055273
Georges Bank is a large, shallow feature separating the Gulf of Maine from the Atlantic Ocean. Previous studies demonstrated a strong tidal-mixing front during the warm season on the northern bank margin between thermally stratified water in the Gulf of Maine and mixed water on the bank. Tides transport warm water off the bank during flood tide and cool gulf water onto the bank during ebb tide. During 10 days in August 2009, we mapped frontal temperatures in five study areas along ∼100 km of the bank margin. The seabed �frontal zone�, where temperature changed with frontal movment, experienced semidiurnal temperature maxima and minima. The tidal excursion of the frontal boundary between stratified and mixed water ranged 6 to 10 km. This �frontal boundary zone� was narrower than the frontal zone. Along transects perpendicular to the bank margin, seabed temperature change at individual sites ranged from 7.0°C in the frontal zone to 0.0°C in mixed bank water. At time series in frontal zone stations, changes during tidal cycles ranged from 1.2 to 6.1°C. The greatest rate of change (−2.48°C hr−1) occurred at mid-ebb. Geographic plots of seabed temperature change allowed the mapping of up to 8 subareas in each study area. The magnitude of temperature change in a subarea depended on its location in the frontal zone. Frontal movement had the greatest effect on seabed temperature in the 40 to 80 m depth interval. Subareas experiencing maximum temperature change in the frontal zone were not in the frontal boundary zone, but rather several km gulfward (off-bank) of the frontal boundary zone. These results provide a new ecological framework for examining the effect of tidally-driven temperature variability on the distribution, food resources, and reproductive success of benthic invertebrate and demersal fish species living in tidal front habitats.
Hapke, C., Kratzmann, M., and Himmelstoss, E., 2013, Geomorphic and human influence on large-scale coastal change:
, v. 199
, pp. 160-170
. Online at 10.1016/j.geomorph.2012.11.025
An increasing need exists for regional-scale measurements of shoreline change to aid in management and planning decisions over broad portion of the coast and to inform assessments of coastal vulnerabilities and hazards. A recent dataset of regional shoreline change, covering a large portion of the U.S. East coast (New England and Mid-Atlantic), provides rates of shoreline change over historical (~150 years) and recent (25-30 years) time periods making it ideal for a broad assessment of the regional variation of shoreline change, and the natural and humaninduced influences on coastal behavior. The variable coastal landforms of the region provide an opportunity to investigate how specific geomorphic landforms relate to the spatial variability of shoreline change. In addition to natural influences on the rates of change, we examine the effects that development and human modifications to the coastline have on the measurements of regional shoreline change.
Hartwell, S.R., Wingfield, D.K., Allwardt, A.O., Wong, F.L., Lightsom, F.L., 2013, Shapefile for Coastal Zone Management Program Counties of the United States and Its Territories, 2009:
U.S. Geological Survey Open-File Report
. Online at 10.3133/ofr20131284
Kratzmann, M.G., Himmelstoss, E.A., Ruggiero, P., Thieler, E.R., and Reid, D., 2013, National Assessment of Shoreline Change: A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the Pacific Northwest Coast.:
U.S. Geological Survey Open-File Report 2012-1008
. Online at 10.3133/ofr20121008
Lentz, E., Hapke, C., Stockdon, H.F., and Hehre, R., 2013, Improving Understanding of Long-Term Barrier Island Evolution through Multi-Decadal Assessment of Mrophologic Change:
, v. 337
, no. 1
, pp. 65-67
. Online at 10.1016/j.margeo.2013.02.004
Observed morphodynamic changes over multiple decades were coupled with storm-driven run-up characteristics at Fire Island, New York, to explore the influence of wave processes relative to the impacts of other coastal change drivers on the near-term evolution of the barrier island. Historical topography was generated from digital stereo-photogrammetry and compared with more recent lidar surveys to quantify near-term (decadal) morphodynamic changes to the beach and primary dune system between the years 1969, 1999, and 2009. Notably increased profile volumes were observed along the entirety of the island in 1999, and likely provide the eolian source for the steady dune crest progradation observed over the relatively quiescent decade that followed. Persistent patterns of erosion and accretion over 10-, 30-, and 40-year intervals are attributable to variations in island morphology, human activity, and variations in offshore bathymetry and island orientation that influence the wave energy reaching the coast. Areas of documented long-term historical inlet formation and extensive bayside marsh development show substantial landward translation of the dunebeach profile over the near-term period of this study. Correlations among areas predicted to overwash, observed elevation changes of the dune crestline, and observed instances of overwash in undeveloped segments of the barrier island verify that overwash locations can be accurately predicted in undeveloped segments of coast. In fact, an assessment of 2012 aerial imagery collected after Hurricane Sandy confirms that overwash occurred at the majority of near-term locations persistently predicted to overwash. In addition to the storm wave climate, factors related to variations within the geologic framework which in turn influence island orientation, offshore slope, and sediment supply impact island behavior on near-term timescales.
McMullen, K.Y., Poppe, L.J., Ackerman, S.D., Blackwood, D.S., Lewit, P.G., and Parker, C.E., 2013, Sea-floor geology in northeastern Block Island Sound, Rhode Island:
U.S. Geological Survey Open-File Report 2013-1003
. Online at http://pubs.usgs.gov/of/2013/1003/
Meighan, H.E., Pulliam, J., ten Brink, U.S., and Lopez-Venegas, A.M., 2013, Seismic Evidence for a Slab Tear at the Puerto Rico Trench:
Journal Geophysical Research
, v. 118
. Online at 10.1002/jgrb.50227
Meighan, H.E., ten Brink, U., Pulliam, J., 2013, Slab tears and intermediate-depth seismicity:
Geophysical Research Letters
, v. 40
. Online at 10.1002/grl.50830
Obelcz, J., Brothers, D., Chaytor, J., ten Brink, U., Ross, S.W., and Brooke, A., 2014, Geomorphic characterization of four shelf-sourced submarine canyons
along the U.S. Mid-Atlantic continental margin:
Deep Sea Research Part 2: Topical Studies in Oceanography
, no. 104
, pp. 106-119
Pe'eri, S., McLeod, A., Lavoie, P., Ackerman, S., and Gardner, J, 2013, Field Calibration and Validation of Remote Sensing Surveys:
International Journal of Remote Sensing
, v. 34
, no. 18
, pp. 6423-6436
The Optical Collection Suite (OCS) is a ground-truth sampling system designed to perform in situ measurements that help calibrate and validate optical remote-sensing and swath-sonar surveys for mapping and monitoring coastal ecosystems and ocean planning. The OCS system enables researchers to collect underwater imagery with real-time feedback, measure the spectral response and quantify the water clarity with simple and relatively inexpensive instruments that can be hand-deployed from a small vessel. This paper reviews the design and performance of the system, based on operational and logistical considerations, as well as the data requirements to support a number of coastal science and management projects. The OCS system has been operational since 2009 and has been used in several ground-truth missions that overlapped with airborne lidar bathymetry (ALB), hyperspectral imagery (HSI), and swath-sonar bathymetric surveys in the Gulf of Maine, southwest Alaska and the U.S. Virgin Islands. Research projects that have used the system include a comparison of backscatter intensity derived from acoustic (multibeam/interferometric sonars) versus active optical (ALB) sensors, ALB bottom detection and seafloor characterization using HSI and ALB.
Pendleton, E.A., Baldwin, W.E., Barnhardt, W.A., Ackerman, S.D., Foster, D.S., Andrews, B.A., and Schwab, W.C., 2013, Shallow Geology, Sea-floor Texture, and Physiographic Provinces of the Inner Continental Shelf from Nahant to Northern Cape Cod Bay, Massachusetts:
U.S.Geological Survey Open-File Report 2012-1157
. Online at http://pubs.usgs.gov/of/2012/1157/
Pohlman, J.W., Riedel, M., Bauer, J.E., Canuel, E.A., Paul, C.C., Lapham, L., Grabowski, K.S., Coffin, R.B., and Spence, G.D., 2013, Increased efficiency of anaerobic methane oxidation in low-organic content seep sediments:
Geochimica et Cosmochimica Acta
Sulfate-dependent anaerobic oxidation of methane (AOM) is the key sedimentary microbial process limiting methane emissions from marine sediments and methane seeps. In this study, we investigate how the presence of low-organic content sediment influences the capacity and efficiency of AOM at Bullseye vent, a gas hydrate-bearing cold seep offshore of Vancouver Island, Canada. The upper 8 m of sediment contains < 0.4 wt% total organic carbon (OC) and primarily consists of glacially-derived material that was deposited 14,900 to 15,900 yrs BP during the retreat of the late Quaternary Cordilleran Ice Sheet. We hypothesize this aged and exceptionally low-OC content sedimentary OM is biologically refractory, thereby limiting degradation of non-methane OM by sulfate reduction and maximizing methane consumption by sulfate-dependent AOM. A radiocarbon-based dissolved inorganic carbon (DIC) isotope mass balance model demonstrates that respired DIC in sediment pore fluids is derived from a fossil carbon source that is devoid of 14C. A fossil origin for the DIC precludes remineralization of non-fossil OM present within the sulfate zone as a significant contributor to pore water DIC, suggesting that nearly all sulfate is available for anaerobic oxidation of fossil seep methane. Methane flux from the SMT to the sediment water interface in a diffusion-dominated flux region of Bullseye vent was, on average, 96% less than at an OM-rich seep in the Gulf of Mexico with a similar methane flux regime. Evidence for enhanced methane oxidation capacity within OM-poor sediments has implications for assessing how climate-sensitive reservoirs of sedimentary methane (e.g., gas hydrate) will respond to ocean warming, particularly along glacially-influenced mid and high latitude continental margins.
Poppe, L.J., McMullen, K.Y., Ackerman, S.D., and Glomb, K.A., 2013, Sea-Floor Geology and Topography Offshore in Northeastern Long Island Sound:
U.S. Geological Survey Open-File Report 2013-1060
. Online at 10.3133/ofr20131060
Poppe, L.J., McMullen, K.Y., Ackerman, S.D., Guberski, M.R., and Wood, D.A., 2013, Sea-floor character and geology off the entrance to the Connecticut River, northeastern Long Island Sound:
U.S. Geological Survey Open-File Report 2012-1103
. Online at http://pubs.usgs.gov/of/2012/1103/
Datasets of gridded multibeam bathymetry and sidescan-sonar backscatter, together covering approximately 29.1 square kilometers, were used to interpret character and geology of the sea floor off the entrance to the Connecticut River in northeastern Long Island Sound. Although originally collected for charting purposes during National Oceanic and Atmospheric Administration hydrographic survey H12013, these acoustic data, sidescan-sonar imagery, and the sea-floor sampling and photography stations subsequently occupied to verify the acoustic data (1) show the composition and terrain of the seabed, (2) provide information on sediment transport and benthic habitat, and (3) are part of an expanding series of studies that provide a fundamental framework for research and resource management (for example, cables, pipelines, and dredging) activities in this major east coast estuary.
Ralston, D.K., Warner, J.C., Rockwell-Geyer, W., and Wall, G.R., 2013, Sediment transport due to extreme events: the Hudson River estuary after Tropical Storms Irene and Lee:
Geophysical Research Letters
, v. 40
, no. 20
. Online at 10.1002/2013GL057906
Ruggiero, P., Kratzmann, M.G., Himmelstoss, E.A., Reid, D., Allan, J., and Kaminsky, G., 2013, National Assessment of Shoreline Change: Historical Shoreline Change in the Pacific Northwest.:
U.S. Geological Survey Open-File Report 2012-1007
. Online at 10.3133/of20121007
Schwab, W.C., Baldwin, W.E., Hapke, C.J., Lentz, E.E., Gayes, P.T., Denny, J.F., List, J.H., and Warner, J.C., 2013, Geologic Evidence for Onshore Sediment Transport from the Inner-Continental Shelf: Fire Island, New York:
Journal of Coastal Research
, v. 29
, no. 3
, pp. 526-544
Sediment budget analyses along the south shore of Fire Island, New York, have been conducted and debated in the
scientiﬁc and coastal engineering literature for decades. It is well documented that a primary component of sediment
transport in this system is directed alongshore from E to W, but discrepancies in volumetric sediment budget calculations
remain. An additional quantity of sand, averaging about 200,000 m3
/y is required to explain the growth of the western
segment of the barrier island, a prograding spit. Littoral sediment derived from updrift erosion of the coast, addition of
beach nourishment ﬁll, and onshore transport of inner continental shelf, shoreface sediments, or both have all been
proposed as potential sources of the additional sediment needed to balance the sediment budget deﬁcit. Analysis of highresolution seaﬂoor mapping data collected in 2011, including seismic reﬂection proﬁles and inteferometric sonar acoustic
backscatter and swath bathymetry; comparison with seaﬂoor mapping data collected in 19961997; and shoreline change
analysis from 1933 to 2011 support previous suggestions that the inner-shelf Holocene sedimentary deposit is a likely
source to resolve this sediment budget discrepancy.
Smith, T, Himmelstoss, E.A., and Thieler, E.R., 2013, Massachusetts Shoreline Change Project: A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the 2013 Update:
U.S. Geological Survey Open-File Report 2012-1183
. Online at http://pubs.usgs.gov/of/2012/1183/title_page.html
Identifying the rates and trends associated with the position of the shoreline through time presents vital information on potential impacts these changes may have on coastal populations and infrastructure, and supports informed coastal management decisions. This report publishes the historical shoreline data used to assess the scale and timing of erosion and accretion along the Massachusetts coast from New Hampshire to Rhode Island including all of Cape Cod, Marthas Vineyard, Nantucket and the Elizabeth Islands. This data is an update to the Massachusetts Office of Coastal Zone Management Shoreline Change Project. Shoreline positions from the past 164 years (1845 to 2009) were used to compute the shoreline change rates. These data include a combined length of 1,804 kilometers of new shoreline data derived from color orthophoto imagery collected in 2008 and 2009, and
topographic lidar collected in 2007. These new shorelines have been added to previously published historic shoreline data from the Massachusetts Office of Coastal Zone Management and the U.S. Geological Survey. A detailed report containing a discussion of the shoreline change data presented here and a summary of the resulting rates is available and cited at the end of the Introduction section of this report.
ten Brink, U.S., Bakun, W.H., and Flores, C.H., 2013, Reply to a comment by Carol S. Prentice, Paul Mann, and Luis R. Peña on: Historical perspective on seismic hazard to Hispaniola and the northeast Caribbean region":
Journal of Geophysical Research
, v. 118
, no. 4
, pp. 1606-1608
Thieler, E.R., Foster, D.S., Mallinson, D.M., Himmelstoss, E.A., McNinch, J.E., List, J.H.,and Hammar-Klose, E.S., 2013, Quaternary Geophysical Framework of the Northeastern North Carolina Coastal System:
U.S. Geological Survey Open-File Report 2011-1015
. Online at http://pubs.usgs.gov/of/2011/1015/
The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system.
Thieler, E.R., Smith, T.L., Knisel, J., and Sampson, D., 2013, Massachusetts Shoreline Change Mapping and Analysis Project, 2013 Update:
U.S. Geological Survey Open-File Report 2012-1189
Information on rates and trends of shoreline change can be used to improve the understanding of the underlying causes and potential effects of coastal erosion on coastal populations and infrastructure and can support informed coastal management decisions. In this report, we summarize the changes in the historical positions of the shoreline of the Massachusetts coast for the 165 years from 1844 through 2009. The study area includes the Massachusetts coastal region from Salisbury to Westport, including Cape Cod, as well as Marthas Vineyard, Nantucket, and the Elizabeth Islands. New statewide shoreline data were developed for approximately 1,804 kilometers (1,121 miles) of shoreline using color aerial orthoimagery from 2008 and 2009 and topographic lidar from 2007.
The shoreline data were integrated with existing historical shoreline data from the U.S. Geological Survey (USGS) and Massachusetts Office of Coastal Zone Management (CZM) to compute long- (about 150 years) and short-term (about 30 years) rates of shoreline change. A linear regression method was used to calculate long- and short-term rates of shoreline change at 26,510 transects along the Massachusetts coast. In locations where shoreline data were insufficient to use the linear regression method, short-term rates were calculated using an end-point method.
Long-term rates of shoreline change are calculated with (LTw) and without (LTwo) shorelines from the 1970s and 1994 to examine the effect of removing these data on measured rates of change. Regionally averaged rates are used to assess the general characteristics of the two-rate computations, and we find that (1) the rates of change for both LTw and LTwo are essentially the same; (2) including more data slightly reduces the uncertainty of the rate, which is expected as the number of shorelines increases; and (3) the data for the shorelines from the 1970s and 1994 are not outliers with respect to the long-term trend. These findings are true for regional averages, but may not hold at specific transects.
Twomey, E.R., and Signell, R., 2013, Construction of a 3 Arc Second Digital Elevation Model for the Gulf of Maine:
U.S. Geological Survey Open-File Report 2011-1127
. Online at http://pubs.usgs.gov/of/2011/1127/
A system-wide description of the seafloor topography is a basic requirement for most coastal oceanographic studies. The necessary detail of the topography obviously varies with application, but for many uses, a nominal resolution of roughly 100 m is sufficient. Creating a digital bathymetric grid with this level of resolution can be a complex procedure due to a multiplicity of data sources, data coverages, datums and interpolation procedures. This report documents the procedures used to construct a 3-arcsecond (approximately 90-meter grid cell size) digital elevation model for the Gulf of Maine (71°30' to 63° W, 39°30' to 46° N). We obtained elevation and bathymetric data from a variety of American and Canadian sources, converted all data to the North American Datum of 1983 for horizontal coordinates and the North American Vertical Datum of 1988 for vertical coordinates, used a combination of automatic and manual techniques for quality control, and interpolated gaps using a surface-fitting routine.
Wagner, J.K.S., McEntee, M.H., Brothers, L.L., German, C.R., Kaiser, C.L., Yoerger, D.R., and Van Dover, C.L., 2013, Cold-seep habitat mapping: High-resolution spatial characterization of the Blake Ridge Diapir seep field:
Deep Sea Research II: Topical Studies in Oceanography
Relationships among seep community biomass, diversity, and physiographic controls such as under-lying geology are not well understood. Previous efforts to constrain these relationships at the Blake Ridge Diapir were limited to observations from piloted deep-submergence vehicles.In August 2012, the autonomous underwater vehicle(AUV) Sentry collected geophysical and photographic data over a 0.131 km2 area at the Blake Ridge Diapir seeps.A nested survey approach was used that began with a regional or reconnaissance-style survey using sub-bottom mapping systems to locate and identify seeps and underlying conduits.This survey was followed by AUV-mounted sidescan sonar and multibeam echo sounder systems mapping on a meso scale to characterize the seabed physiography. At the most detailed survey level,digital photographic imaging was used to resolve sub-meter characteristics of the biology. Four pockmarks (2570m diameter)were documented,each supporting chemosynthetic communities.Concentric zonation of mussels and clams suggests thei nfluence of chemical gradients on megafaunal distribution. Data collection and analytical techniques used here yield high-resolution habitat maps that can serve as baselines to constrain temporal evolution of seafloor seeps,and to inform ecological niche modeling and resource management.
Waite, W.F., and Spangenberg, E, 2013, Gas hydrate formation rates for dissolved-phase methane in porous laboratory specimens:
Geophysical Research Letters
, v. 40
, no. 16
, pp. 4310-4315
. Online at 10.1002/grl.50809
Marine sands highly saturated with gas hydrates are potential energy resources, likely forming from methane
dissolved in pore water. Laboratory fabrication of gas hydrate-bearing sands formed from dissolved-phase
methane usually requires 1Ã¯Â¿Â½2 months to attain the high hydrate saturations characteristic of naturally occurring
energy resource targets. A series of gas hydrate formation tests, in which methane-supersaturated water circulates
through 100, 240, and 200,000 cm3 vessels containing glass beads or unconsolidated sand, show that the rate-limiting
step is dissolving gaseous-phase methane into the circulating water to form methane-supersaturated fluid. This
implies that laboratory and natural hydrate formation rates are primarily limited by methane availability. Developing
effective techniques for dissolving gaseous methane into water will increase formation rates above our observed
(1 ÃÂ± 0.5) Ãï¿½ 10−7 mol of methane consumed for hydrate formation per minute per cubic centimeter of pore space,
which corresponds to a hydrate saturation increase of 2 ÃÂ± 1% per day, regardless of specimen size.
Warner, J.C., Defne, Z., Haas, K., and Arango, H.G, 2013, A wetting and drying scheme for ROMS:
Computers & Geosciences
, v. 58
, pp. 54-61
The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud ﬂats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always ﬂow into any cell, but prevents outﬂow from a cell when the total depth in that cell is less than a user deﬁned critical value. We describe the method, the implementation into the three- dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water ﬂows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.