Lisbon, Portugal Geology

Lisbon, Geology The city lies on seven hills, not counting the smaller hills. In the Atlantic Ocean, near Cadiz, there is an east-west tectonic fault, the so-called Gloria leaf shift. Two other tectonic features, the Gorringe Bank and the Marquês-de-Pombal fault, are located at the southern coast of Portugal. Earthquakes are a consequence of the northward drifting African plate colliding with the Iberian Peninsula (Eurasian plate). In addition, numerous active mud volcanoes in the Gulf of Cadiz indicate ongoing seismic activity in the region. Due to the past earthquakes, observation points were established on the seabed in 2004. They are intended to measure temperature and pressure fluctuations that indicate tensions in the earth's crust that can be discharged in an earthquake.