Northeast Seismic & Long Island Fault Recon
Automated USGS earthquake telemetry, regional fault line architecture (Ramapo Fault & Cameron's Line), and glacial sand sediment liquefaction mechanics across Suffolk and Nassau.
Northeast US & Tri-State Seismic Activity (Past 7 Days)
Regional Fault Systems & Ancient Tectonics
Bedrock to Glacial MoraineThe Ramapo Fault System
Distance: ~35 Miles West of Nassau CountySource of the Magnitude 4.8 Tewksbury, NJ earthquake on April 5, 2024 that shook all of Long Island.
Cameron's Line (Subterranean Suture)
Distance: Passes directly beneath western Sound watersMajor Appalachian tectonic collision zone. Produces occasional micro-tremors (M1.5 - M2.5) felt in Queens and Nassau.
14th Street & East River Fault Zones
Distance: ~15 Miles West of Nassau BorderGenerated the historic August 10, 1884 Magnitude 5.2 Rockaway earthquake that cracked chimneys in Jamaica and Hempstead.
Unlike Manhattan which sits on solid metamorphic crystalline bedrock (Manhattan Schist), Long Island is a massive pile of glacial terminal moraine sand, clay, and gravel sitting atop a gently sloping bedrock surface up to 2,000 feet underground.
When seismic waves travel across the Hudson River and hit Long Island's thick layer of loose sandy sediment, the waves slow down and amplify in amplitude. This acts like a bowl of gelatin, creating noticeable rolling motion felt across high-rises, hospitals, and residential homes in Nassau and Suffolk.
Citizen science reports help seismologists map ground motion intensities (Modified Mercalli Intensity scale) across Long Island neighborhoods.