1. Reconstructing Sea Levels in
Venice, Italy from 1700 to 1872
Nick Angelini
Laura Corsetto
David DeFusco
Michael Scarsella
In cooperation with CNR
Advisors: Dario Camuffo
Alberto Gallo
Emanuela Pagan

2. Artic cap area decrease since 1979
Introduction
Social Implications
-Tide levels have been rising all over the world for centuries.
-The melting of polar ice caps has caused much of this sea level rise
9% area decrease per decade
20% area decrease since 1979
-Industrial revolution effects starting in 1860
*Is the rise in sea level natural, or has man influenced it?
Artic cap area decrease since 1979
(NASA)

3. Introduction
-The rising rate of the sea level in Venice is unknown from 1700 to 1872.
-Gap needs to be filled in order to fully analyze contributing factors behind rising sea levels.
-Acqua Alta occurs 20 times per year on average.
St. Mark’s square, September, 2001

4. Mission Statement
Using similar photographic analysis methods, accurate paintings will be examined to determine what the sea levels were during the time period of each of the paintings. By applying data collected from paintings, photos, and engravings in canal walls, this project will verify Camuffo’s results and provide a more accurate reconstruction of sea levels in Venice from 1700 to 1872, when automated tide gauges came online.

5. Approach Understand background information
Create appropriate methodology
Results and analysis
Conclusion

6. Background Selected artists C markers Photographs
Dario Camuffo’s results

7. Venetian Artists Who? When? Why rely on Venetian art?
Canaletto
Bellotto
Guardi
Why rely on Venetian art?
Accuracy
Camera obscura
Antonio Givanni "Canaletto" Canal ( )

8. Camera Obscura Primitive lens system Extremely accurate for its time
How it works:
Light through lens
Mirror reflects light onto surface
Canvas placed on surface
“Photographic” image created

9. Camera Obscura Primitive lens system Extremely accurate for its time
How it works:
Light through lens
Mirror reflects light onto surface
Canvas placed on surface
“Photographic” image created

10. Camera Obscura Primitive lens system Extremely accurate for its time
How it works:
Light through lens
Mirror reflects light onto surface
Canvas placed on surface
“Photographic” image created

11. La Punta Della Dogana (1727)
Venetian Paintings
Canaletto’s “Disciples” Belloto and Guardi
Notice algae line
Average high tide level
Comune Marino
La Punta Della Dogana (1727)

12. C markers C markers Documents comune marino per year
Etched in stone on canal walls
Many locations unknown (WPI-IQP)

13. Photographs Earliest known photos of Venice (mid-1800s)
Will be used in coalition with paintings
More accurate than paintings
Later timeframe for extended dataset

14. Project Techniques Reconstruct sea levels
Present-day replication of views
Paintings, Photographs
Waterline differential (height)
Photo measurements vs. on-site measurements
Plot data of average sea level Vs. time (yrs)
Data comparison to global warming statistics
Apply information to or from C-Marker data

15. Learning from the Past…
Dario Camuffo (CNR)
Originator of sea-level construction concept.
Learn from his work
(11 paintings used)
Improve upon his work
Two additional approaches
Photographs
C markers
Dario Camuffo of CNR

16. …Applying toward the Future
Selection of Venetian landscape portraits
Database created
Utilized Catalogue Raisonné
Catagorized appropriately for future use
Date, Image, Source, other info.
Narrowed down by visible Comune Marino line

17. Digital Reproductions
Map locations of paintings
Obtain copies of photographs
Map locations
Go to locations
Take digital photos of present-day views
Measure to fixed points near and far, in 3 dimensions.
Document Data
Map of sea levels and painting locations

18. Waterline Differential
Record on-site measurement data
Measure same distances within photo/portrait.
Create a ratio (scale)
Distance from comune marino in comparison to today.
Derive Quantitative data
Water level in year of each photo/portrait.

19. Waterline Differential Cont.
Side-by-side comparison of photos
Obvious comune marino shift
Example shows a 44 cm +/- 10 shift since 1880
Side-by-Side gives visual confirmation of numeric data
Photo Courtesy of Dario Camuffo, 2002

20. C-Markers
Dated C-Markers checked for support to tide progression trend
If not dated – possible to date with tide information.
Height corresponds to year on tide progression chart.
Markers photographed and documented for database.
Treated as a tertiary source for data if deemed reliable.

21. Results and Analysis Create graphical representations of data
Graphs, charts, tables, database
Comparison of data
Global warming
Look for human influences
Pre-recorded tide data since 1872
Look for correlation

22. Graphical Representation
Gather relevant data
Height differential
Year of photo/portrait
Plot data points
Tide progression

23. Data Comparison
Compare tide progression line with global warming data

24. Comparison to Tidal Data
KEY: Left to Right
Canaletto & Bellotto
Photographs
Tide Gauge data (Blue)
 measured sea level since 1872
Courtesy of Dario Camuffo

25. Conclusion Ultimately aid researchers Thank You! Known tidal levels
Two Centuries prior to what is currently known
Comparable to global warming data
Discover human influence on sea level rise
Find a cause for sea level rise since 1700