The sailboat being under sail and having less manouverability than the PWC or powered personal water craft has the right of way and should be avoided by the power boat to prevent a collision in case the sailboat has to change direction relative to the wind like tacking.
Predicting earthquakes is a very complex task as compared to that of the volcanic eruptions that take place as a consequence of these quakes. Not even the USGS can accurately predict these earthquakes as an earthquake occurs from deep within the layers of the earth and thus it is quite difficult to predict how shallow these depths are.
<u>Monitoring and predicting the behavior</u> of an active or extinct or dominant type of volcano is much easier as they can be studied based on magma and lava, for example, the swelling inside a volcano can predict that magma has accumulated near the surface.
Movement of magma and gases through the hydrothermal vents can be done through the thermal monitoring system also a volcano can bee seen on the surface and a earthquake in the seismic wave form underneath the surface is not.
Because the soviet union and america owned east germany which had a good economy while west germany had german rule and a low economy but in november 1991 they agreed in taking the berlin wall down and reuinting germany.
