Measuring earthquakes

A strong earthquake hit Pakistan on October 26 leaving more than 270 dead. The Richter being a logarithmic scale, an earthquake of magnitude 8 is 10 times stronger than a 7 magnitude earthquake. So what was the intensity of the earthquake? In the epicentre, it was 7.5, according to the US Geological Centre (USGC). With my Chilean experience, the USGC estimates are fairly accurate, given with a variation of one or two decimals. How is it possible that the National Meteorological Centre located thousands of kilometres away in Karachi measures an earthquake stronger than in the epicentre? But what was its strength? I turned to the NDMA website for an update with the strength of the of the seismic movement in different cities of Pakistan. But we do not yet have any such information.
It is not possible to predict an earthquake with date and time but the chances of a big one are always possible when the seismic gap is sufficient. So measuring tremors and earthquakes in many locations is very important; keeping records is also important and all this aids in calculating the seismic gaps in different cities. Is there a national seismic measurement system in place? Do we have a seismographic centre in the northern areas or in Islamabad? We have to do better. Pakistan is a country where earthquakes and tremors are frequent and a better and trustworthy system for their measurement is required.
Catalina Alliende
Islamabad