Why is material amplification important

Like I said at the beginning, CPA is particularly useful in places where raw laser power, and particularly In the same way that lasers gave us nonlinear optics, CPA has been integral in the development of This isn't only 'more', it's qualitatively different: it pushes nonlinear optics to regimes where It has also helped push the study of light-matter interaction past that same perturbative limit, giving us the tools to extract electrons from molecules and control them in very precise ways, thereby allowing for the creation of tools like e.

Decide on the meaning of the saying, significance and implications of the same. Start here for a quick overview of the site Or why did it happen to you? Or, to put another way, there are as many or more answers to this question as there are applications of the polymerase chain reaction PCR , for which Mullis received the Nobel prize.

Auxesis is a specific type of amplification in which words are piled on in order of importance, ending with the most important or triumphant part. Learn more about hiring developers or posting ads with us With G ZR, you can mix-and-match modules at both ends, something that was previously impossible. He feels lack of confidence in him. Fort Mason is built on bedrock, and the Marina District that was damaged in is built on soft sediment.

The geologic foundation material made all the difference. In October , the time bomb went off. Figure shows seismograms of an aftershock of magnitude 4.

The waves were also of much lower frequency. An analogy is commonly made between these two types of site and a bowl of jello on a table, an experiment that can be done at home.

Then jolt the table sideways. The blocks on the jello will fall over, whereas the blocks directly on the tabletop might remain standing. The shaking of the blocks on the table illustrates the effect of a seismic wave passing through bedrock.

When the shaking reaches the bowl of jello, however, the waves are amplified so that the top of the jello jiggles and causes the blocks to topple. In a similar fashion, the soft foundation materials at a soil site will amplify the seismic waves, which results in much more vigorous shaking than would be expected at a rock site. A tragic illustration of this phenomenon was provided by the magnitude 8.

Actually, the epicenter of the earthquake was in the Pacific Ocean on a subduction zone, hundreds of miles from Mexico City. It is called the Mexico City Earthquake because of the terrible losses suffered by that city. More than fifteen million people live in Mexico City, many in substandard housing, which was one reason why so many lives were lost.

But more important is the geologic foundation: Mexico City is built on the former bed of Lake Texcoco. The clay, silt, and sand of this ancient lake, in part, saturated with water, greatly amplified the seismic waves traveling from the subduction zone. More than five hundred buildings fell down, and more than ten thousand people were killed.

Much of the foundation of these cities is soft sediment: deltaic deposits of the Fraser and Duwamish rivers, glacial deposits in Puget Sound, and alluvial deposits of the Willamette and Columbia rivers. Even though a subduction-zone earthquake would be far away, near the coast or offshore as it was for Mexico City , these soft sediments would be expected to amplify the seismic waves and cause more damage than if the cities were built on bedrock. Fortunately for the people of the Pacific Northwest, building standards are higher than those in Mexico City in , so we would not expect as high a loss of life.

In addition, geotechnical experience with many earthquakes around the world permits a forecast of the effects of near-surface geology on seismic waves from various earthquake sources.

In other words, this is a problem we can do something about. Because no two earthquake sources are alike, Wong and his colleagues programmed computer simulations based on a Cascadia Subduction Zone earthquake of M w 8. Because the surface effects are strongly influenced attenuated by the distance of a site from the epicenter, they used distances from the crustal source to the site of five, ten, and fifteen kilometers 1.

What property of a seismic wave is best for determining the hazard to buildings? Acceleration is the rate of increase in the speed of an object. If you step off a cliff and fall through space, your speed will accelerate from zero at a rate of 32 feet 9.

This is an acceleration of 1 g. When an earthquake has a vertical acceleration greater than 1 g, stones or clods of earth are thrown into the air, as first observed during a great earthquake in India in Vertical accelerations greater than 1 g were recorded during the San Fernando, California, Earthquake, with the result that a fire truck with its brakes set was tossed about the Lopez Canyon Fire Station, leaving tire marks on the garage door frame 3 feet above the floor.

Horizontal accelerations may be measured as well. However, it is important to consider complications associated with landslides. Landslides induced by the Kashmir earthquake have been addressed in several studies, from different perspectives. Owen et al. According to Kamp et al. Dellow et al. And as mentioned earlier, Shafique et al. In summary, the major controlling factors for landslides induced by the Kashmir earthquake were 1 human activity Owen et al.

In our study, we analyzed landslide aspects with respect to the point of maximum release of energy CMT solution. Keeping in mind factors such as human activity and bedrock lithology beside the relation of landslides with the fault trace, it is uncertain at which stage of the rupture the landslides have been triggered.

It could be because of the initial rupture used by Shafique et al. The Kashmir earthquake was a shallow earthquake. In such case a seismic wave field will reach the surface at an angle, rather than vertical when originating a larger distance away. This can lead to the creation of a so-called shadow zone effect due to deep valley blocking the propagation of a seismic wave field into a topographic feature. This phenomenon has also been observed in this study.

Because of this shadow effect, ridges show de-amplification instead of amplification location d and e in Fig. The detailed topography of low areas can be found in Fig.

These deep valleys can also be seen with the blue profile line in Fig. These valleys restricted the impact of seismic waves on the next ridge s away from the CMT. Thus the ridges, which are normally supposed to show amplification because of trapping, show de-amplification instead. This effect however, may not be visible for deep-seated seismic sources or sources at a larger epicentral distance. The deeper or further away the source of the earthquake, the more vertical will be the incoming seismic wave field.

A similar effect is possible if we have significantly reduced seismic velocities close to the surface, due to, e. The results of the study can be used as an important parameter for seismic microzonation of the study area to mitigate the negative impacts of earthquakes. Topography affects the diffraction and reflection of incident seismic waves, thereby amplifying or de-amplifying the seismic response.

Overall, topography-induced amplification of seismic response is found on ridges and slopes facing away from the CMT location and de-amplification is found in valleys and at the bottom of slopes facing towards the CMT location, which is consistent with previous studies. All data sources have been cited in this article, and the results can be reproduced by adopting the methodology. SK, MvdM, and HvdW prepared the original draft, while all authors contributed to the review and editing. Visualization and graphics were designed by SK and MvdM.

All authors have read and reviewed the paper. The damage data were obtained from Shafique et al. We are thankful to Steven de Jong and one anonymous referee for their valuable input.

This research has been supported by the University of Twente grant no. This paper was edited by Maria Ana Baptista and reviewed by Steven de Jong and one anonymous referee. Ali, Z. Ashford, S. Athanasopoulos, G. Avouac, J. Bassin, C. Bauer, R. Bhukta, S. India, 69, —, Bouckovalas, G. Casarotti, E. Dellow, G. Dhanya, J. Dunning, S. Earth Planet. Evangelista, L. Hartzell, S. Hayes, G. Hough, S. Hussain, A. Hussain, S. Johnson, M. Kamp, U. Hazards, 54, 1—25, Komatitsch, D.

Kramer, S. Kumagai, H. Lee, S. Asian Earth Sci. Leprince, S. Liu, Q. Magnoni, F. Makra, K. Meunier, P. Owen, L. Paolucci, R. Parsons, T.

Patera, A. Pathier, E. Peter, D. Pilz, M. Qi, S. Raghukanth, S. Hazards, 46, 1—13, Restrepo, D. Saba, S. Shafique, M. Earth Obs. Smerzini, C. Spudich, P. Taborda, R. Wang, F.