The St James Lowlands are a protrusion of continental crust stuck to the Fhysay oceanic plate. To the west of the Fhysay/Arsae subduction zone lies the St James subcontinent, called the Hashash (Icelands) in Whitehall and Morrun Vie (Vanishing Land) in Thangrodom. In Tharsi, it is the Hurror (Suffering Cold). The subcontinent effectively makes the Doon plateau.
Extending some five hundred leagues north of the plateau in a wide teardrop shape, the lowlands are broad alluvial plains. Mostly flat, the highest point of the lowlands is about two hundred feet above sea level if one eliminates the Doonish foothills. Some few islands lie off the coasts, almost entirely runoff and sandbars. In the winder, the west side of the lowlands is often icelocked. The east side is occasionally icelocked, but the prevailing currents swing wide north around the teardrop, sheltering the east. This creates polynya north of the goblinmounts where immense numbers of arctic wildlife, walrus, penguins, seals, etc. shelter from the winter.
Not in all years does this polynya form. In particularly cold winters, ice will push as far south as the Invedeletch coast. This is a 1% event, but results in immense hardship for the aquatic animals. Such freezes are called ‘Dyings’ by goblins.