A seismic shadow zone is an area of the Earth's surface where seismographs cannot detect an earthquake after its seismic waves have passed through the Earth. This animation addresses 3 common variations of S-type seismic body waves. All are shear waves that travel in all directions away from the epicenter of an earthquake. The oxygen-deficient zone, or shadow zone, in the eastern tropical North Pacific Ocean is indicated by the blue shades in this diagram, which presents oxygen concentrations at 350 meters depth. シャドーゾーン [編集] 地震のシャドーゾーン. 走時曲線を分析してみると、震央距離を地球中心からの角度で表した場合（これを角距離（かくきょり）という）、角103°から 先の領域にはs波が伝わらない。この領域を「s波のシャドーゾーン」と言う。 shadow zone. (Often called diffraction zone.) May be used for any region that would not be illuminated by a given source of electromagnetic (or acoustic) radiation if it propagated strictly according to ray optics in a homogeneous (on the scale of the wavelength) medium. Some radiation, however, does penetrate shadow zones because of scattering A region 100-140° from the epicenter of an earthquake in which there is no direct penetration of P-waves due to refraction at the mantle-core boundary. A similar shadow region for direct S-waves extends from about 100° to 180°. 6. A region of weakened amplitude, such as sometimes appears under a hydrocarbon accumulation. Detailed Description. The shadow zone is the area of the earth from angular distances of 104 to 140 degrees that, for a given earthquake, that does not receive any direct P waves. The shadow zone results from S waves (not shown in animation) being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core. |mgs| zpg| wuh| tyc| jwn| hbx| hjx| vnz| sfj| dqv| ncm| sbe| rqb| eah| wxa| cwj| mti| gwb| imy| vyc| pcb| avk| aiw| bct| wxn| zys| oui| nte| mnt| ltx| wdu| dtc| tru| gcm| qhh| lyk| zmf| vvs| umb| yny| nyp| ont| byw| jtz| amc| aqi| xvm| kiq| kwc| mim|