Institute of Astronomy, ETH-Zentrum,CH-8092 Zürich, Switzerland

The emission measure of the quiet corona, defined by the plasma hotter than one million degrees, is fluctuating in nearly every 1900km x 1900km pixel observed by EIT on SOHO. In the average, the larger the emission measure in a pixel, the more it fluctuates. Increases in emission measure constitute a major energy input into the corona, suggesting that the lower corona is not just heated, but continuously replenished by chromospheric material heated to coronal temperatures. The temporal sequence of brightenings has been determined by cross-correlations of identical picture elements in different emissions. The method allows to study statistically the faintest fluctuations in the corona and relate them to the layers below. The radio emission peaks before the coronal emission measure, similar to the Neupert effect in flares, but shows considerable variation relative to O V. These statistical results show that the coronal heating events follow the properties of regular solar flares and thus may be interpreted as nanoflares. Assuming that nanoflares behave follow the same scaling as flares. The hard X-ray flux can be estimated and strategies for HESSI observations may be developed.