performed, taking into account the increased seismic hazard and the vulnerability of the exposed elements at risk (e.g. local population and the building stock). Finally, the risk can, theoretically at least, be mitigated, either through reductions to the hazard or a reduction to the exposure or the vulnerability. Causes There are many ways in which induced seismicity has been seen to occur. In the 2010s, some energy technologies that inject or extract fluid from the Earth, such as oil and gas extraction and geothermal energy development, have been found or suspected to cause seismic events. Some energy technologies also produce wastes that may be managed through disposal or storage by injection deep into the ground. For example, waste water from oil and gas production and carbon dioxide from a variety of industrial processes may be managed through underground injection. Artificial lakes The column of water in a large and deep artificial lake alters in-situ stress along an existing fault or fracture. In these reservoirs, the weight of the water column can significantly change the stress on an underlying fault or fracture by increasing the total stress through direct loading, or decreasing the effective stress through the increased pore water pressure. This significant change in stress can lead to sudden movement along the fault or fracture, resulting in an earthquake. Reservoir-induced seismic events can be relatively large compared to other forms of induced seismicity. Though understanding of reservoir-induced seismic activity is very limited, it has been noted that seismicity appears to occur on dams with heights larger than . The extra water pressure created by large reservoirs is the most accepted explanation for the seismic activity. When the reservoirs are filled or drained, induced seismicity can occur immediately or with a small time lag. The first case of reservoir-induced seismicity occurred in 1932 in Algeria's Oued Fodda Dam. The 6.3 magnitude 1967 Koynanagar earthquake occurred in Maharashtra, India with its epicenter, fore- and aftershocks all located near or under the Koyna Dam reservoir. 180 people died and 1,500 were left injured. The effects of the earthquake were felt away in Bombay with tremors and power outages. During the beginnings of the Vajont Dam in Italy, there were seismic shocks recorded during its initial fill. After a landslide almost filled the reservoir in 1963, causing a massive flooding and around 2,000 deaths, it was drained and consequently seismic activity was almost non-existent.