Natural catastrophe is the term used when a natural event is so intense that people suffer and material assets are affected to a substantial degree and on a more or less large scale. Whether a natural event results in a natural catastrophe depends not so much on the absolute force of the event as on the vulnerability of the affected region. An earthquake of magnitude 6.5 will have no effect at all in an uninhabited desert. In a region that is well-prepared it will cause comparatively little damage, but will cause a catastrophe in a town that has made inadequate preparations. A "great" natural catastrophe is defined by the United Nations as a natural catastrophe that distinctly exceeds the ability of an affected region to help itself and makes supraregional or international assistance necessary. As a rule this is the case when there are thousands of fatalities and hundreds of thousands of people made homeless or substantial economic losses - depending on the economic situation of the country affected.