Seismic wave order of 10–50 km or so around the world. Dense arrays of nearby sensors such as those that exist in California can provide accuracy of roughly a kilometer, and much greater accuracy is possible when timing is measured directly by cross-correlation of seismogram waveforms. Seismic wave Seismic waves are waves of energy that travel through the Earth's layers, and are a result of earthquakes, volcanic eruptions, magma movement, large landslides and large man-made explosions that give out low-frequency acoustic energy. Many other natural and anthropogenic sources create low-amplitude waves commonly referred to as ambient vibrations. Seismic waves are studied by
Natural beech wood global climate changes can also have a profound effect on what kind of natural woodland can grow and survive in a specific area. European beech is usually more susceptible to climatic changes than soil-composition and the current global climate change are found to affect the geographical distribution of natural beech wood habitats. The term "Natural" is often confusingly used as a synonym for "Primeval". While primeval woodlands that still exists, are indeed natural, natural woodlands does not have to be primeval per se. Secondary or re-established woodlands can also be natural; it is just a matter of whether a given