Traffic jams are nothing new for Southern California. But what’s happening at the ports of Los Angeles and Long Beach is truly historic. Record demand for imported goods, beginning in mid-2020, coupled with shortages of truckers, shipping containers and other equipment, has slowed ship unloading and left dozens of vessels waiting offshore.

Satellite images, collected from the European Space Agency’s Sentinel 2 satellite show typical congestion before and during the pandemic. Each dot on the graphic below shows an unscientific census of ships large enough to see from space. Each image is from the middle of the month.

The L.A.-Long Beach port complex is the principal gateway for products that American consumers and businesses buy from Asia. It is also Exhibit A for the supply chain issues that are dogging the economic recovery.

Ship placements are approximations based on satellite imagery and placed manually. Clouds and other imagery issues can result in undercounts.

David Lynch contributed to this report.