Perhaps you didn’t realize that beneath our feet lies a story of geological drama. We are standing near Wobbe See Erdfall. This seemingly peaceful spot is linked to Hamburg’s very own earthquake zone.
The area around Bahrenfeld, Othmarschen, and Groß Flottbek experiences minor tremors and sinkholes. These geological events led to the formation of the Wobbe See Erdfall. Its origin is tied to the Othmarschen Langenfelde Diapir. This is the largest salt dome beneath Hamburg.
Imagine a massive salt deposit stretching from the Elbe near Othmarschen. It extends 20 kilometers to Schnelsen and almost to Quickborn. This salt dome reaches depths of up to nine kilometers. Near the Altona hospital, it almost touches the surface.
Salt domes are not very stable. When groundwater seeps in, large cavities or caverns can form. If these caverns collapse, it results in a sinkhole. The Wobbe See Erdfall was created this way.
Sinkholes have occurred repeatedly in the Bahrenfeld and Groß Flottbek area over the centuries. For example, in 1771, five large oak trees vanished into a suddenly formed hole. Even the small Wobbe See Erdfall near the Flottbeker Markt originated from such an event.
Until 2017, ground subsidence was recorded here. The ground sank almost six millimeters in just two and a half years. This caused cracks in nearby buildings.
Since 1800, about 30 mini-earthquakes have been recorded in the Groß Flottbek area. All of them were triggered by sinkholes.
The last significant tremor occurred on April 8, 2009. It was strong enough to frighten people. Some residents even left their houses. An aftershock followed an hour later. The quake was likely caused by a collapse within the salt dome at a depth of about 100 meters.
Relatively strong earthquakes also occurred in 1960, 1983, and 2000. These events damaged buildings and caused power outages.
Despite this seismic activity, authorities consider the earthquake risk to be minimal. So, while we enjoy the scenery around Wobbe See Erdfall remember the hidden geological forces at play. They have shaped this landscape and continue to remind us of nature’s power.