When Superstorm Sandy hit New York, a lot of people had questions.

Talke: “One of the first things that happens when a big event like that occurs is people ask, when did this happen before? Is this the biggest in history?”

That’s Stefan Talke, an assistant professor of civil and environmental engineering at Portland State University. His curiosity was also piqued, but he could not find reliable answers. So he sent a student to the U.S. national archives to photograph hand-written tidal records dating back to 1844. Then they entered the data into spreadsheets.

This allowed Talke to identify the highest storm tide – the combined effect of a storm surge and regular high tide – for each year.

He found that the storm tide in New York Harbor has increased by nearly a foot. Add sea level rise, and you now have maximum water levels two and a half feet higher in New York Harbor during major storms.

Talke: “Now the big question is why is this happening? And there’s a couple different theories.”

Climate change plays a part, as could local factors, like the deepening of shipping channels and the destruction of wetlands. Overall, it makes New York more vulnerable to storm tides.

Reporting credit: ChavoBart Digital Media.
Photo: Lower Manhattan Skyline and New York Harbor from the Brooklyn Bridge Park in Dumbo. Copyright protected.

More Resources
Increasing storm tides in New York Harbor, 1844–2013
Odds of storm waters overflowing Manhattan seawall up 20-fold, new study shows: newfound rise of storm tides by almost a foot since 1844 adds to risk from sea-level rise
3-minute video of Stefan Talke explaining how tide levels were automatically recorded in the nineteenth century: Increasing Storm Tides in New York Harbor
Homogeneous record of Atlantic hurricane surge threat since 1923