Seismology

The sixteenth entry is a acumulação de tensão, and the noun inside it has to be unpacked twice by an English reader. A tensão does several jobs in Portuguese: it is the voltage in a cable, the tension in a rope or in a room, and what a rock is under before it breaks. English splits that last job in two and guards the border between the halves. « Stress » is the force acting on each unit of area, which is what is applied to the rock. « Strain » is the deformation that follows, which is what the rock does about it. They are not degrees of one thing and they are not synonyms: a bar can be under great stress and show almost no strain. So the phrase on this page is « stress accumulation », and « strain accumulation » is not a loose variant of it but a second, real quantity, the one geodesy measures at the surface. Two further notes. Everyday « stress » is the pressure a person is under and carries none of this precision. And the word that answers « strain » is a deformação, never a tensão.