Climate Change, Coastal geologic Hazards and Sea-Level Rise

1. CLIMATE CHANGE,
COASTAL GEOLOGIC HAZARDS
and
SEA-LEVEL RISE
URI Climate Change Symposium
18 November 2011
Jon C. Boothroyd
Rhode Island State Geologist,
Research Professor Emeritus – Quaternary Geology
-------------
Rhode Island Geological Survey and Department of Geosciences
College of the Environment and Life Sciences
University of Rhode Island
jon_boothroyd@uri.edu

2. Southern New England, Long Island, Continental Shelf ~ 26,000 yBP
Map Generated By:
BA Oakley and JC Boothroyd

3. THE LAST NORTH AMERICAN
ICE SHEETS
CORDILLERAN
LAURENTIDE
-
You are
here
After Dyke & Prest, 1987

4. MALASPINA GLACIER – Northeast Gulf of Alaska
-
An Analog “The size of Rhode Island”

5. Oakley, 2011
You are
here
Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010

6. Oakley, 2011
Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010

7. Oakley, 2011
Charlestown
Moraine
Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010

8. Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010
Oakley, 2011

9. Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010
Oakley, 2011

10. Oakley, 2011
Ice margins modified from:
Dyke and Prest, 1987
Ridge, 2010; Goss, 1993
Smith, 2010

11. Eustatic
Sea-Level
Rise
+
Isostatic
Rebound Laurentide
at Ice Sheet?
Laurentide
2m.100yr-1
Ice Sheet?
Block Island 2m.100yr-1
Antarctic Ice
Antarctic Ice
Sheet?
Sheet? -1
2-5m.100yr
2-5m.100yr-1
Explanation
- 390 ft
Oakley and Boothroyd,
submitted 2011

12. -165 ft
Begin Meltwater Pulse 1B
Post-Glacial
Lake
Atlantic Ocean

13. -130 ft
End Meltwater Pulse 1B
Post-Glacial
Lake
Estuary
Atlantic Ocean

14. When Contemplating Rhode Island
Coastal Geologic Hazards
One Must Consider:
• Extratropical Cyclones (“Nor’easters”)
• Hurricanes (Tropical Cyclones)
• and ……. Sea Level Rise

15. When Contemplating Rhode Island
Coastal Geologic Hazards
Which Give Rise to these Processes:
• Frontal Erosion – from Breaking Waves
and Swash
• Storm-Surge Overwash
• Elevated MHHW into the Future

16. When Contemplating Rhode Island
Coastal Geologic Hazards
The Scale of Processes are:
• Breaking Waves – 3 to 10+ feet at shoreline
• Storm-Surge Overwash – 1 to 10+ feet water
depth across shore zone
• Sea-Level Rise – 0.14 inches per year at present

17. The Sea May Be Rising Long Term – But…..
Instantaneous Storm Surges
Elevate Sea Level Now

18. Narragansett Pier Seawall – Patriots Day 2007
WPRI.com
16 apr 2007

19. Patriots Day Extratropical Storm – April 2007
Newport Tide Gauge
SET UP PREDICTED
http://tidesandcurrents.noaa.gov/
STORM SURGE data_menu.shtml?stn=8452660%20Newport,%20RI&type=Tide+Data

20. Overwash -
Browning Cottages
RE Hehre

21. Frontal Erosion - Browning Cottages
BA Oakley

22. Frontal Erosion 1939-2006 -
Browning Cottages
2011
2006
1939

23. Charlestown Beach
Overwash
RE Hehre

24. Charlestown Beach – Hurricane Bob 1991
Washover Fan Deposition
Removal is a Bad Idea …….
Barriers Naturally Retreat
Landward and Upward Aug 1991

25. Watch Hill – Hurricane Carol, 1954
But… Sometimes there is no alternative
Providence Journal, 1954

26. A General Coastal Barrier Model for Rhode Island

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

28. Napatree Barrier – Shoreline Change Maps
2004 – Sound Side
1939 – Sound Side
1939 – 2004 – Ocean Side
Ocean Side
Hehre and Boothroyd, 2007

29. Tidal
Datums
Newport MHHW = 3.85 ft
3
“Zero” in some NAVD 1988 = 2.05 ft
data sets 2
MSL = 1.74ft New MSL
and on maps
NGVD 1929 = 1.18 ft Old “MSL”
1
MLLW = 0.0 ft
0
-1
Adapted from:
www.ngs.noaa.gov/newsys-cgi-
bin/ngs_opsd.prl?PID=LW0493&E
POCH=1983-2001

30. How High
will the
Water Be? Boothroyd and
Hehre 2008
9.46 Feet Above MHHW
Tidal
Heights
Newport
MHHW = 3.85 ft
MLLW = 0.0 ft Adapted from: www.ngs.noaa.gov/newsys-cgi-
bin/ngs_opsd.prl?PID=LW0493&EPOCH=1983-2001

31. Frequency?
Next Month or
Next Year
Tropical Storm
Irene Aug 2011
Adapted from
NOAA;
USACE 1988;
Hehre 2007

32. Lastly,
Climate Change
and the
Future Shore Zone
of
Rhode Island

33. Greenland Outlet Glaciers
Change from Polythermal to Warm Based
A Key to Future Sea-Level Rise

34. Brathwaite, 2002

35. HEIGHT NOW
Adapted from:
http://tidesandcurrents.noaa.gov/sltrends/
sltrends_station.shtml?stnid=8452660%20Newport,%20RI
Boothroyd 2011

36. Observed Global Sea Level Rise ... Accelerating
IPCC
18 cm rise since 1900 2001
Current rate:
estimate
3.3 cm per decade
Rahmstorf, Cazenave, Church, Hansen, Keeling, Parker and Somerville (Science 2007)

37. Global Sea Level Linked to Global Temperature
Projection of Sea-Level Rise 1990 - 2100
Using IPCC 2007 Temperature Projections
Extreme
Projection
IPCC 2007
Vermeer and Rahmstorf, 2009,
PNAS, v106, p 21537-21532

38. Height above NOW
New
Estimate
Low
3.3 ft Range 100 cm
1.1 ft 35 cm
2050

39. Height above NOW
New 140 cm
4.6 ft
Estimate
Mid
1.4 ft 42 cm
2050

40. 6.2 ft Height above NOW 190 cm
New Estimate High Range
1.6 ft 50 cm
2050

41. Misquamicut Headland – 100 Yr Hurricane Surge
+ 3 feet Sea
Level Rise
Present
Outdated
Flood Map

42. Misquamicut – US 1A – Westerly
1938 Hurricane - Debris Swath
Debris Swath after Barrier
Sea-Level Rise
Providence Journal, 1938

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

44. Ninigret – Green Hill Lagoons
1938 Storm Surge + SL Rise after 1938
11 ft above MHHW
Today

45. Ninigret – Green Hill Lagoons
1938 Storm Surge + SL Rise
11 ft above MHHW
Today
Frosty
Drew
Foster
Cove Area

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

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

48. Ninigret – Green Hill Lagoons
2100 Inundation – 5 ft
200 ft Barrier Migration
Projected Frosty
Drew
Foster
Cove Area

49. Wickford Marketplace – In-Place Inundation “The Bathtub Ring”
Today
10 Sept 2010 Teresa Crean

50. End of Presentation

52. THE HOCKEY STICK The Message
Temp lags
CO2
Medieval Warm Period Little Ice
Age
Moberg et al, 2005