In plate tectonics, a passive margin is the normally gently sloping continental shelf area located on the trailing edge of a drifting continent. The passive margin is free of the seismic and volcanic activity associated with the subduction, rifting or transform faulting that is the result of plate tectonic activity. Bridge across the Álfagjá rift valley in southwest Iceland, the boundary of the Eurasian and North American continental tectonic plates. ...  Sediment  Rock  Mantle  The global continental shelf, highlighted in cyan The continental shelf is the extended perimeter of each continent, which is covered during interglacial periods such as the current epoch by relatively shallow seas (known as shelf seas) and gulfs. ... Color-coded regions of the world based on the seven commonly-recognised continents Dymaxion map by Buckminster Fuller shows land masses with minimal distortion as nearly one continuous continent A continent is one of several large areas of land on Earth, which are identified by convention rather than any strict... Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the movement of waves through the Earth. ... This article is about volcanoes in geology. ... The Juan de Fuca plate sinks below the North America plate at the Cascadia subduction zone. ... In geology, a rift is a place where the Earths lithosphere is expanding. ... A transform fault is a geological fault that is a special case of strike-slip faulting which terminates abruptly, at both ends, at a major transverse geological feature. ... The tectonic plates of the world were mapped in the second half of the 20th century. ...

Present-day examples include the eastern seaboards of North America and South America, and all shores of Africa except for the active Mediterranean and Red Sea margins. World map showing North America A satellite composite image of North America. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... A world map showing the continent of Africa. ... Composite satellite image of the Mediterranean Sea. ... Location of the Red Sea The Red Sea is an inlet of the Indian Ocean between Africa and Asia. ...