3. A minimal volume of 5 ml of a pooled BAL sample is needed for BAL cellular analysis. The optimal volume is 10 to 20 ml. It is acceptable to pool all aliquots of the retrieved BAL ï¬uid for routine analyses (including the ï¬rst retrieved aliquot). 4. BAL cell differential counts with greater than 15% lym-
So when a continent meets a continent, no subduction occurs (instead, the plates collide and thicken). True subduction happens only to oceanic lithosphere. When oceanic lithosphere meets continental lithosphere, the continent always stays on top while the oceanic plate subducts.
The common points where the plates touch one another is where the earthquake starts or the focus. As seen in the picture above, subduction zones are on the borders of each tectonic plate. As they crash together one plate moves below the other which causes subduction zone earthquakes. Earthquakes are one of the biggest natural disasters known to man. Earthquakes occur when there is a sudden release of energy below the earths crust at the focus.