Vowel the vowel sounds of "flower", , form a triphthong or disyllable, depending on dialect. In phonology, diphthongs and triphthongs are distinguished from sequences of monophthongs by whether the vowel sound may be analyzed into different phonemes or not. For example, the vowel sounds in a two-syllable pronunciation of the word "flower" () phonetically form a disyllabic triphthong, but are phonologically a sequence of a diphthong (represented by the letters ) and a monophthong (represented by the letters ). Some linguists use the terms "diphthong" and "triphthong" only in this phonemic sense. The name "vowel" is often used for the symbols
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