When one of the rifts opens into the existing ocean, the rift system is flooded with seawater and becomes a new sea.
This model is consistent with near orthogonal rifting along the entire length of the rift system.
The Mesozoic structures underneath the North Sea can be seen as a failed rift system.
Volcanism and a rift system developed in the central North Sea area where basaltic lavas were extruded.
An aborted rift system or half gruben was created.
The typical rift system consists of three rift arms at approximately 120 degree angles.
The core is mass of mountain peaks (6,000-7,000 ft.) considered part of the east rift system, and represents one third of the area.
The rift system was also found to contain the largest subglacial lakes in Antarctica.
The resulting rift system failed but has remained as an aulacogen (a scar or zone of weakness) deep underground.
When the African plate separated from North America, this created an aborted rift system or half gruben.