sentence2_structure: Seismologists<>measured<>the intensity of an earthquake with the mercalli scale<>originally
sentence1: Seismologists with the Iceland Meteorological Office believe that further earthquakes, measuring up to 7 on the Richter scale, could hit the same area over the next few decades.
sentence2: Seismologists originally measured the intensity of an earthquake with the mercalli scale.
question: How did seismologists originally measure the intensity of an earthquake?