As early as the 1970s, studies revealed that climatic changes such as melting and reforming glaciers can stress Earth's crust, augmenting or even triggering active volcanism and tectonic plate movement. Even though these ideas have appeared in print since then, more studies are supporting glacial retreat and sea level rise as strong triggers for earthquakes and volcanic eruptions. For example, recent research demonstrated that thinning of the Vatnajokull ice cap (the largest ice cap in Iceland) is causing pressure decrease in the mantle beneath the ice. On a smaller scale, worldwide, there have been more than 100 earthquakes induced by filling reservoirs with water (with magnitudes of 2.0-6.5). According to Evgeny Podolskiy, Nagoya University, Japan, "With the upper layers of Earth's crust vulnerable to such small-scale external forces, and increasing environment change fomenting these effects, the result is likely to be an increase this century in the number of seismic catastrophes induced by human activities."