The San Andreas fault in California has reached its highest level of strain in the last 1,000 years - and that's exactly what makes it so dangerous. Running nearly 1,300 kilometres, from Palm Springs to the San Francisco Bay, the fault has been quiet for decades. And it's precisely that quiet that has let an enormous pressure build up.

Geologists analysed data collected over an entire millennium to gauge the future danger. The conclusion: strain is historically high, mainly because the last century has seen no major earthquake to release the accumulated energy. In other words, the longer the silence lasts, the stronger the blow being prepared.

Still, the science stays honest about what it doesn't know. Seismologist Dr. Lucy Jones warns that "for a geologist, 'soon' can mean 'in the next century'." The study says the danger is rising, but can't answer the one question everyone wants - when. Harold Tobin of the University of Washington points to the worst-case scenario: two faults rupturing at once, which would be far more devastating than an ordinary quake. For comparison, the Loma Prieta earthquake in San Francisco in 1989 took 63 lives.

For us in the Balkans, this isn't some exotic foreign story. The region sits on its own faults and knows all too well what it means when the ground shakes - Skopje 1963, the recent tremors next door. The difference is in readiness: while California spends billions on studies and building codes, here the question of how safe the buildings we live in actually are still gets unconvincing answers. The silence before an earthquake is the same everywhere - the only thing that differs is how prepared we are for the moment it ends.