The mystery of what shook the Jersey Shore on Thursday afternoon has been solved.

Four F-16 jets (Christian Petersen/Getty Images)

Naval Air Station Patuxent River in Maryland on its Facebook page explains that two supersonic jets on routine testing and training are to blame for creating a sonic boom that shook the ground along the New Jersey, Delaware and Maryland coastlines early on Thursday afternoon.

Many people reported to police and media outlets that the ground shook like an earthquake but the United States Geological Society did not show seismic activity along the east coast. Gina Callegari Truchan of Brick posted on the Jersey Shore Hurricane News Facebook page her front door shook "vigorously."

The cold air is partially responsible for amplifying the boom. Stefanie J. Baxter tells the Wilmington News-Journal that cold air helps to amplify sonic booms.