Excavations Unlock New York City’s Dramatic Geologic Foundation

A decade of subterranean excavations on the Third Water Tunnel, the Second Avenue Subway, and the Long Island Rail Road’s East Side Access Project has provided geologists with unprecedented access to New York City’s physical structure.

1 minute read

February 22, 2014, 9:00 AM PST

By James Brasuell @CasualBrasuell


Sam Roberts provides a glimpse of the excitement experienced by geologists in recent years as they’ve explored the subterranean levels of New York City. Quoted int he article is Tony Hiss, the author of The Experience of Place, who describes what’s so exciting about New York’s foundation: “New York’s deepest and darkest secret, its oldest and most violent and previously only vaguely glimpsed history is finally coming to light — the schist that formed three-quarters of a billion years ago, when colliding continents compressed an ancient ocean; the even more elusive amphibolite, three times harder than concrete, that’s a slow-cooked remnant of islands as big as Japan off the New York shoreline.”

New York City's geology has also had a marked impact on the country’s most famous real estate market: “The application of that theory illustrates why skyscrapers historically sprouted downtown and in Midtown, but not in between. The bedrock — the formidable Manhattan Schist on which their concrete foundations rest — is closest to the surface in those two areas, though, nowadays, the technology exists to build almost anywhere.”

Monday, February 17, 2014 in New York Times

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Wastewater pouring out from a pipe.

Alabama: Trump Terminates Settlements for Black Communities Harmed By Raw Sewage

Trump deemed the landmark civil rights agreement “illegal DEI and environmental justice policy.”

April 13, 2025 - Inside Climate News

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 16, 2025 - Diana Ionescu

Black and white photos of camp made up of small 'earthquake shacks' in Dolores Park in 1906 after the San Francisco earthquake.

The 120 Year Old Tiny Home Villages That Sheltered San Francisco’s Earthquake Refugees

More than a century ago, San Francisco mobilized to house thousands of residents displaced by the 1906 earthquake. Could their strategy offer a model for the present?

April 15, 2025 - Charles F. Bloszies

Calvary Street bridge over freeway in Indianapolis, Indiana.

Indy Neighborhood Group Builds Temporary Multi-Use Path

Community members, aided in part by funding from the city, repurposed a vehicle lane to create a protected bike and pedestrian path for the summer season.

1 hour ago - Smart Cities Dive

Holland Tunnel, vehicular tunnel under Hudson River that connects New York City neighborhood of SoHo in Lower Manhattan to east with Jersey City in New Jersey.

Congestion Pricing Drops Holland Tunnel Delays by 65 Percent

New York City’s contentious tolling program has yielded improved traffic and roughly $100 million in revenue for the MTA.

3 hours ago - Curbed

People walking up and down stairs in New York City subway station.

In Both Crashes and Crime, Public Transportation is Far Safer than Driving

Contrary to popular assumptions, public transportation has far lower crash and crime rates than automobile travel. For safer communities, improve and encourage transit travel.

April 18 - Scientific American