On a recent Sunday morning, Glade was leading her earth surface processes class on a field trip to Chimney Bluffs State Park in Wayne County when the group encountered a fresh collapse along the shoreline.
“A chunk of this cliff has fallen off and we’re gonna try to go over it,” she said.
“It’s an adventure.”
Erosion at the Chimney Bluffs is expected. The formations are made of glacial drumlins: long, smooth hills left behind when a massive ice sheet retreated at the end of the last ice age.
When the ice melted, it formed Lake Ontario, and water began reshaping the hills almost immediately.
Since then, waves have eaten away at the base of the cliffs while rain cuts into the top, leaving behind steep, fragile ridges that continue to shift.
For visitors like Liz Thompson, an environmental science student in the class, the bluffs are striking in both beauty and instability.
“In the sun, the cliffs kind of almost look pink against like this blue, really blue, giant lake that almost looks like an ocean,” she said. “It's something you just wouldn't expect to see here.”
She also sees signs of movement everywhere along the shoreline.
“There’s a lot of tiny failure points,” she said. “You can kind of see grasses hanging over or trees almost at a kind of extreme slant, like they're almost about to fall over the cliff.”
Some of that erosion is driven by Lake Ontario itself. High water can allow waves to undercut the base of the cliffs, making them more likely to collapse.
In 2017, high water caused erosion that forced state officials to close sections of trails along the cliffs.
Pictures of the most recent collapse have reignited a debate on social media over lake level management as a potential cause of increased erosion.
Lake level management has been blamed for extreme coastal flooding in recent years, despite evidence that the high water was actually caused by snowmelt followed by rain.
Heavy rain has been a factor in the years since the Lake Ontario flooding. When soil becomes saturated, it can lose the ability to maintain its shape.
“It basically like pushes the grains apart, makes them less stable, and there's less friction between the grains, and that can lead to something like a landslide or debris flow,” she said.
That dynamic may also help explain a recent landslide in Irondequoit, where saturated ground caused a hillside to give way and forced at least one family to evacuate after officials deemed their home unsafe.
Glade said events like this are part of how landscapes behave, but their frequency and intensity can vary.
“It’s just good for people to be aware that erosion is like a common phenomenon everywhere in the world,” she said. “Sometimes these events happen on time scales that are just long enough for people to forget that they are a sort of natural process in landscapes,” she said.
She cautions against drawing conclusions from any single event, but notes that changing climate conditions can influence the intensity of storms and rainfall.
“We expect a kind of flashier system as the climate warms. So there might be longer spells of droughts, and then when it rains, it's more intense, because the atmosphere can actually hold more water before it dumps it on us.”
For students studying the landscape, the changes are not abstract.
“I think that it's important to study and get a better understanding of how exactly it's going to affect our climate and our landscapes and all the processes that go into shaping the world into what it looks like,” said student Julia Dubey.
The Chimney Bluffs is a unique place to do that, but Glade says exploring this landscape can help scientists understand more about the world around us, and the forces that shape it.
