Coastal Geologic Hazards and Sea-Level Rise: Climate Change in Rhode Island This presentation was given at the Shoreline Change SAMP Stakeholder Meeting on April 4th, 2013 by Jon C. Boothroyd (Rhode Island Geological Survey and Department of Geosciences, University of Rhode Island) and Bryan A. Oakley (Environmental Earth Science Department, Eastern Connecticut State University).

1. COASTAL GEOLOGIC HAZARDS
AND SEA-LEVEL RISE:
CLIMATE CHANGE IN RHODE ISLAND
Shoreline Change SAMP Stakeholders Meeting
4 April 2013
Jon C. Boothroyd1,2and Bryan A. Oakley3
(1) Rhode Island Geological Survey
(2) Department of Geosciences, University of Rhode Island, Kingston RI 02881
(3) Environmental Earth Science Department, Eastern Connecticut State
University, Willimantic, CT 06226

2. Summary for Rhode Island:
• Glacial Geology, Past and Present,
the Underlying Key to Understanding Processes and
Products
• Storms the Most Important Driver in Coastal Change
Sea-Level Rise a Secondary Effect
• Shoreface Sediment Transport Not Well Understood
at Present
• Future Major Storms Combined With Sea-Level Rise
a Very Large Problem
• Accelerated Sea-Level Rise Resulting in Inundation
also a Very Large Potential Problem
• RICRMC Planning for a 3-5 foot Rise by 2100 and a
1.5 foot Rise by 2050

3. S New England, E New York, Continental Shelf at LGM ~ 26,000 yBP
You are
here RI
Map Generated By:
BA Oakley and JC Boothroyd

4. Eustatic
Sea-Level
Rise
+ Isostatic
Rebound
Isostatic
Rebound
at Laurentide
Block Island Ice Sheet?
Laurentide
2m.100yr-1
Ice Sheet?
RI Relative 2m.100yr-1
Sea Level
Antarctic Ice
Sheet?
Eustatic 2-5m.100yr-1
Sea Level
Explanation
Oakley and Boothroyd,
July 2012

5. Geomorphology
of
Southeastern
New England

6. Narragansett Pier, RI Seawall – Tropical Storm Irene 2011
Storms are the Driver
Anonymous via N Vinhateiro, 28 aug 2011

7. Frontal Erosion - Browning Cottages
BA Oakley

8. Superstorm Sandy - Browning Cottages
30 Oct 2012
http://fema.maps.arcgis.com/home/webmap/viewer.html?webmap=

9. Superstorm Sandy - Browning Cottages
31 Oct 2012

10. Frontal Erosion 1939-2012 -
Browning Cottages, Moonstone Beach, RI
House 2012
moved to
Upland
1951

11. Shoreface – Inner Shelf Deposition
Block Island Sound
Offshore Movement of Sand

12. Sandy Geologic Summary:
• Sandy a Tropical – Extratropical Hybrid
• Significant Wave Height 31 feet at Inner Shelf Buoy;
Max Recorded Wave Height 47 feet
• RI Received a Glancing Blow ; But Public
Misconception by Some Believe it a 100 Year Event
• Greatest Geologic Change and Infrastructure
Damage Since Hurricane Carol, 1954
• Washover Fan Deposition an Underestimated
Problem
• Shoreline Change Special Area Management Plan
Needed to Better Prepare for Next Event – Already
Started

13. Superstorm Sandy – Tropical-Extratropical Hybrid
29 October 2012
Newport Tide Gauge
SET UP
PREDICTED
http://tidesandcurrents.noaa.gov/
STORM SURGE data_menu.shtml?stn=8452660%20Newport,%20RI&type=Tide+Data

14. How High Maximum Water Level
was the 9.46 Feet, 2.88 meters
Above MHHW
Water ? Boothroyd and
Carol Water Level Hehre 2008
Why above
MHHW?
Sandy Water Level
Water
4.25 Feet, 1.30 meters
Levels Above MHHW
Newport, RI
MHHW = 3.85 ft, 1.173 m
Adapted from:
www.ngs.noaa.gov/newsy
s-cgi-
MLLW = 0.0 ft, 0.0 m bin/ngs_opsd.prl?PID=LW
0493&EPOCH=1983-2001

15. Frequency?
Next Month or
Next Year
Superstorm Sandy
Oct 2012
Tropical Storm
Irene Aug 2011
Hurricane Bob
Aug 1991
Adapted from
NOAA;
USACE 1988;
Hehre 2007

16. Measuring Shore Transects with:
“2 Sticks and A String” or, the Modified Emery Method
-22cm
Eric Woodward 12 Oct 2012

17. Cha-Ez Profile - Charlestown Barrier - Post Sandy
Washover Fan
Deposition
S McCandless
30 Oct 2012

18. Post
Sandy Pre-Sandy
FEMA Dune
Erosion
Protocol

19. Charlestown Beach – Blizzard 1978 – No Berm
JC Boothroyd

20. Post
Sandy
Blizzard
1978

21. Elevation Washover Fan
Deposition
Difference –
USACE Post
Sandy and 2011
USGS LiDAR
DEMs
Charlestown
Barrier Foredune
Removal
Cha-Ez
Profile
DRAFT FIGURE –
PRELIMINARY RESULTS

22. Pre-Sandy – Quonochontaug Barrier
Conservation Land
Washover Fan
Deposition
Bousquet and Son – Aerial Views

23. Post-Sandy –
Quonochontaug Barrier
Conservation Land
Washover Fan
Deposition
Bousquet and Son – Aerial Views

24. A General Coastal Barrier Model for Rhode Island
Very Transgressive

25. Napatree Barrier – Westerly, RI
Little Narragansett Bay
Watch Hill
Hehre and Boothroyd, 2007

26. Napatree Barrier – Shoreline Change Map
2004 – Sound Side
1939 – Sound Side
-71.6m
1939 – 2004 – Ocean Side
Ocean Side
Hehre and Boothroyd, 2007

27. Washover Fan Deposition
Misquamicut Barrier - Westerly
Atlantic Ave
Washover Fan
RI DOT
30 Oct 2012

28. Charlestown Beach, RI – Hurricane Bob 1991
Washover Fan Deposition
Removal is a Bad Idea …….
Barriers Naturally Retreat Aug 1991
Landward and Upward JC Boothroyd

29. Deposition and Damage
Misquamicut Headland - Westerly Washover Fan
Andrea
MSQ - And
Hotel
Profile
RI DOT
30 Oct 2012

30. Misquamicut Andrea
Hotel
Shoreline
“Protection”
Structure –
Late 1950s to
Early 1960s
1957
Ford
Providence Journal?

31. Andrea Hotel - Misquamicut Headland - Westerly
The Managed Retreat Begins
Frieda Squires, Providence Journal 10 mar 2013

32. The Fate of Washover Fans –
Misquamicut State Beach
And Hopefully, the Exercise of
Scott Rasmussen
Scientific Rationale for Replenishment 15 Feb 2013

33. A Very Brief Look
at
Climate Change
and the
Future Shore Zone
of
Rhode Island

34. Co2now.org 394.37
www.350.org
http://www.esrl.noaa.gov/gmd/ccgg/trends/co2_data_mlo.html

35. HEIGHT NOW
Adapted from:
http://tidesandcurrents.noaa.gov/sltrends/
sltrends_station.shtml?stnid=8452660%20Newport,%20RI
Boothroyd 2012

36. 6.1 ft 185 cm
VR Max
4.5 ft VR A1F1 137 cm
VR B1 100 cm
Height above NOW
1.4 ft 41
2050

37. Ninigret – Green Hill Lagoons
2003 – 2004 Orthophoto
Today

38. Ninigret – Green Hill Lagoons
2100 Inundation – 5 ft
200 ft Barrier Migration
Projected

39. Ninigret – Green Hill Lagoons
2100 Inundation – 5 ft
+ 1938 Hurricane Surge Event
Projected

40. South Kingstown, RI – Town Beach
An Eroding Glacial Bluff Shore
BA Oakley

41. South Kingstown, RI – Town Beach
An Eroding Glacial Bluff Shore
Boardwalk
Pilings
RI DOT
30 Oct 2012

42. Headland Erosion – Glacial Stratified Bluff
28m

43. Matunuck Headland, S Kingstown
Shoreline Change 1951 - 2012
Projected Change
2012 - 2050 2050
2012
1951

44. End of Presentation