Beaches & Shores Conference 2009 Presentation

Page 1

Tidal Prism Reduction, Backbarrier Infilling, and Inlet Closure: The Evolution of the Plum Island, MA Barrier System in Response to Slow Sea Level Rise

Christopher Hein (BU), Duncan FitzGerald (BU), Emily Carruthers (MIT/WHOI), Allen Gontz (UM-B) Byron Stone (USGS) Northeast Beaches Conference 2009 Northeast Chapter of the International Erosion Control Association

9 June 2009


Study Area: Plum Island

Merrimack River

Gulf of Maine Woods Hole

Plum Island Castle Neck

N 0

2 km

Cape Ann


Stratigraphic Database Merrimack River

Stratigraphic Data Sources:

N

0

2 km

• McIntire & Morgan, 1963, LSU Technical Report • USGS Water Supply Paper, 1963 • McCormick, 1968, Ph.D. Thesis • Hartwell, 1970, ONR Report • Rhodes, 1971, USACE Technical Memo

Parker River

• Anderson-Nichols, 1987, unpub. cores Rowley River

• Som, 1990, MS Thesis • Mass. State Boring Data

Parker River Inlet Castle Neck

• Hein et al., cores

Topographic / Bathymetric Data Sources: • US Coast & Geodetic Survey Hydrographic Survey Soundings (19531954) • Mass GIS DTM Files (2003)


Data Collection

N 0

2 km

• 20 km of Ground Penetrating Radar, 100 & 200 MHz antenna (blue lines) • 7 vibracores, max. 4 m depth (green dots) • 10 Geoprobe cores, max. 15 m (red dots) • 11 auger drill cores, max. 38 m (yellow dots)


Plum Island Stratigraphy 0 Median Grain Size Mean Grain Size

Barrier

Depth (m)

5

10

Backbarrier 15

20

Glaciomarine Clay (Presumpscot) 0

5

Grain Size (ÎŚ)

10

Well Sorted

Poorly Sorted

Sorting

Very Poorly Sorted


Plum Island Stratigraphy: Surface N 2 km

Parker River 3m+ Elevation with respect to MLW (m)

0

Merrimack River

Rowley River Plum Island River

Western edge of Plum Island barrier sands

Parker River Inlet

Ipswich River

-15 m

Tidal Range: 2.7 m Calculated Tidal Prism: 82 x 106 m3


Plum Island Stratigraphy: Backbarrier Base N 2 km

3m Elevation with respect to MLW (m)

0

-15 m (-)

Merrimack River Parker River Rowley River Ipswich River


Backbarrier Sediment Thickness N 2 km

18 m

Thickness (m)

0

0m

NET VOLUME: 850 x 106 m3


Sediment Reservoirs

Salisbury Beach: 11.9

(vol. x 106 m3)

Merrimack ETD: 0.5

Other Reservoirs: Merrimack Paleo-delta: 1300

Plum Island: 77

Offshore Holocene Sand Sheet: 121

Parker / Ipswich ETD: 2.9 Castle Neck: 4.2 Essex ETD: 0.3

Plum Island Backbarrier: 850

Coffins Beach: 8.5

Data Sources: • • • • • • • •

Barnhardt et al., 2009 Costas et al., unpub. Dougherty, 2002, MS Thesis FitzGerald et al., 2002, Geomorph Hein et al., unpub. Hubbard, 1971, MS Thesis McKinlay, 1996, MS Thesis Oldale et al., 1983, Quat. Res. ETD Volumes: inlet cross-sectional areas, Jarrett’s, O’Brien’s & Walton & Adams Relationships


Massachusetts Post-Glacial Sea Level History

Modified from Oldale et al., 1993, Quat. Res.


Evolution of Plum Island Barrier System

Modified from: FitzGerald et al., 1993, in Davis, 1993


Evolution of Plum Island Barrier System 0

Spit Progradation

100 -5

150 200

0

50 m

Spit Platform

250

-10

Modified from Hayes and Kana, 1976

Depth (m)

TWT (nS)

50

1 MHW


Evolution of Plum Island Barrier System


Evolution of Plum Island Barrier System

0

1 MHW

100 150

-4

200 250

-8

Depth (m)

TWT (nS)

50


Evolution of Plum Island Barrier System Paleo-Parker Inlet • Positioned east of modern Parker River • Geophysical & stratigraphic evidence of active inlet system • Southerly migration due to longshore current occasionally punctuated by ebb-breaching events • Eventual closure & overtopping by southerly building spit


Northern Massachusetts Calibrated Sea Level Curve


Plum Island Stratigraphy: Backbarrier Sediments N 2 km

3m+ Elevation with respect to MLW (m)

0

-15 m

Merrimack River Parker River Rowley River Ipswich River


Backbarrier Stripping + 0.5 m Volume Sediment Removed: 600 x 106 m3 Tidal Prism: 143 x 106 m3

Backbarrier Stripping Volume Sediment Removed: 660 x 106 m3 Tidal Prism: 155 x 106 m3

Backbarrier Stripping - 0.5 m Volume Sediment Removed: 723 x 106 m3 Tidal Prism: 165 x 106 m3


Backbarrier Stripping + 0.5 m Volume Sediment Removed: 600 x 106 m3 Tidal Prism: 143 x 106 m3

Backbarrier Stripping Volume Sediment Removed: 660 x 106 m3 Tidal Prism: 155 x 106 m3

Backbarrier Stripping - 0.5 m Volume Sediment Removed: 723 x 106 m3 Tidal Prism: 165 x 106 m3


Backbarrier Stripping + 0.5 m Volume Sediment Removed: 600 x 106 m3 Tidal Prism: 143 x 106 m3

Backbarrier Stripping Volume Sediment Removed: 660 x 106 m3 Tidal Prism: 155 x 106 m3

Backbarrier Stripping - 0.5 m Volume Sediment Removed: 723 x 106 m3 Tidal Prism: 165 x 106 m3


Merrimack Inlet X-C Area: 1900 m2 TP: 25 x 106 m3

Parker Inlet X-C Area: 3100 m2 TP: 40 x 106 m3

Essex Inlet X-C Area: 1700 m2 TP: 23 x 106 m3


Paleo-Merrimack Inlet X-C Area: 1200 m2 TP: 16 x 106 m3

Paleo-Parker Inlet X-C Area: 1300 m2 TP: 18 x 106 m3

Paleo-Essex Inlet X-C Area: 950 m2 TP: 13 x 106 m3


Paleo-Inlets: Combined TP: 47 x 106 m3 Combined X-C Area: 3450 m2

Backbarrier: Tidal Prism: 155 x 106 m3 Equivalent Inlet X-C Area: 13,100 m2

Residual: Tidal Prism: 108 x 106 m3 Equivalent Inlet X-C Area: 8900 m2


Paleo-Inlets: Combined TP: 47 x 106 m3 Combined X-C Area: 3450 m2

Modern Inlets: Combined TP: 88 x 106 m3 Combined X-C Area: 6700 m2

Backbarrier: Tidal Prism: 155 x 106 m3 Equivalent Inlet X-C Area: 13,100 m2

Residual: Tidal Prism: 67 x 106 m3 Equivalent Inlet X-C Area: 5300 m2


Paleo-Plum Island Inlet 1 MHW

0

100 150

-4

Depth (m)

TWT (nS)

50

200 -8

250 0

1

100

200

1300 m2

300

-10

-15 400

50 m

-20

Depth (m)

TWT (nS)

-5


Acknowledgements Funding: NSF Graduate Research Fellowship Program, US Minerals Management Service, GSA Graduate Student Research Grant, AAPG Student Grant, AGU Tilford Field Studies Scholarship, BU Undergraduate Research Opportunities Program, Clare Booth Luce Foundation Field / Lab Assistants: Dr. Walter Barnhardt USGS), Mary Ellison, Carol Wilson, Christine Harrington, Dr. Susana Costas, Nicholas Cohn, Nick Howes, Brandy Rinck, Stephanie Simms, Jeff Grey (USGS), Dr. Britt Argow (Wellesley College) Parker River National Wildlife Refuge Staff


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.