Modern western square dance of "patter calls" and "singing calls", the two types of square dance calls. The logos shown on the right are the international square dance logo and the modern Alliance of Round, Traditional and Square-Dance logo. Modern western square dancing is a non-competitive activity. There are no dance competitions, and apart from fun events, no prizes are ever offered or sought for 'best dancer' or 'best square'. Particularly at the 'challenge' levels there is large degree of personal satisfaction to be gained from the problem solving element of completing a dance. At all levels the main elements are to enjoy the
Types of volcanic eruptions Types of volcanic eruptions Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions. The most well-observed are magmatic eruptions, which involve the decompression of gas within magma that