地震术语英语

Seismic

地震

abnormal events: Coherent events which are not reflections. Refraction, reflected refractions, diffractions, surface waves, and sometimes multiple reflections are included (though there’s nothing ―abnormal‖ about any of these ).

异常同相轴：相干非反射同相轴，包括折射波、反射折射波、绕射波、面波，往往也包括多次反射波（尽管这些波本身无任何异常）。

absorption: A process whereby some of the energy of seismic wave is converted into heat while passing through a medium. Absorption for seismic waves is perhaps of the order of 1/2 db/cycle. Sometimes claimed to be proportional to the frequency squared rather than linear with frequency. See Q.

吸收作用：为地震波通过某一介质时，其一部分能量转化为热量的一个过程。地震波吸收衰减约为每周期1/2 分贝，有时表述为吸收与频率的平方成正比，而不是与频率成简单的线性正比关系。见品质因数Q。

acoustic:Sonic; pertaining to sound. Usually refers to compressional P waves, sometimes restricted to P-waves in fluids (liquids and gases ), sometimes generalized to include other elastic wave types.

声学的，声的：声音的，声速的；属于声学范畴。通常指压缩纵波，有时仅指在流体中传播的纵波（液体和气体），广义上也包括其它类型的弹性波。

acoustic impedance: Seismic velocity multiplied by density.

Reflection coefficient depends on changes in acoustic impedance.

声阻抗，波阻抗：地震波速度乘以介质密度。反射系数依赖于波阻抗的变化。

acoustic wave: 1.Sonic wave. An elastic wave train, sometimes restricted to propagation though a fluid. 2. The wave train generated and detected by a sonic-logging sonde（see acoustic log）. The wave train is a composite of various modes of energy transfer. The first arrival usually results from compressional (P- or longitudinal ) waves traveling in the formation; the inverse of its velocity is measured by the sonic log.

A second arrival is sometimes identified as shear (S-) wave travel in the formation; it represents a pseudo-Rayleigh wave which travels at approximately the velocity of S-waves. Compressional waves traveling through the mud usually have relatively high frequency content; they are sometimes called fluid waves. One or more modes of high-amplitude, low-frequency tube waves (sometimes called Stoneley waves ) are usually very distinct arrival. 3. More generally, an elastic wave or seismic wave.

声波，地震波：1. 声波。有时仅指在流体中传播的弹性波列。2.由声波测井电极系产生并检测到的波列（见声波测井）。该波列是由各种不同能量的波复合而成的。初至波通常是在岩石中传播的压缩（P-或纵）波；其波速的倒数是通过声波测井而测到的。续至波往往被看作在岩石中传播的剪切（S-）波；它表现为一个以近似S-波速度传播的伪-瑞雷波。通过软泥层的压缩波通常具有相对较高的频率成分；往往被称为流

体波。一个或更多强振幅、低频率的管波（也称斯通利波）的波至通常特别明显。3. 更一般的指弹性波或地震波。

air gun: 1. A marine seismic source which injects a bubble of highly compressed air into the water. Oscillations of the bubble as it alternately expands and contracts generate a sonic wave whose frequency depends on the amount of air in the bubble, its pressure, and the water depth (or water pressure ). Arrays of guns of different sizes are sometimes used so that a broader frequency spectrum will be generated. Different from gas gun. 2. Air guns have also been adapted for lowering in a borehole or pushed down into the marsh. The adaptations prevent mud, sand, etc., from entering and fouling the air gun. 3. Air guns are also used in small tanks of water which are set on the surface of the ground as a seismic source on land.

空气枪：1.通过向水中排放高压气泡的一种海上地震震源。气泡交替收缩和膨胀的振动可产生声波，该声波的频率取决于气泡中空气量、压力和水深（或水压）。通常使用大小不同的空气枪阵列来得到更宽的频谱。它不同于单个气枪震源。

2.空气枪通过改进后，可适用于钻孔和沼泽地区。这种改进可阻止泥浆、沙等进入和阻塞空气枪。

3. 空气枪也可以放在地表小型水池中作为陆上地震震源。

air wave: Energy from the shot which travels in the air at the velocity of sound:

1051(1+0.00218 F)1/2≈1051+1.1 F ft/sec, where F=F ahrenheit temperature, or 331.51(1+0.00366 C)1/2≈331.5+0.607 C m/sec, where C=Centigrade temperature.

空气波：爆炸产生的能量在空气中以声速传播：1051(1+0.00218 F)1/2≈1051+1.1 F英尺/秒，其中F为华氏温度，或331.51(1+0.00366 C)1/2≈331.5+0.607 C 米/秒，其中C为摄氏温度。

angle of incidence:The acute angle which a raypath makes with the normal to an interface. This is the same angle as an approaching wavefront makes with an interface in an isotropic medium. The angle between the raypath and the normal is the angle of incidence in the anisotropic case, the raypath not necessarily being perpendicular to the wavefront in this case. The angle of incidence may be complex for electromagnetic waves.

入射角：射线路径与界面法线所成的锐角。在各向同性介质中它等于波阵面与分界面的的夹角。在各向异性介质中，射线路径与界面法线的夹角为入射角，而此时射线路径与波阵面不一定是正交的。对于电磁波来说它的入射角为复角。apparent velocity: 1. The velocity which a wavefront appears to have along a line of geophones. If the wavefront makes the angle θwith the spread and the true velocity of the wavefront if V, then the apparent velocity is V/cosθ. 2. The inverse of the slope of a refraction time-distance curve.

视速度：把波阵面看作沿地面测线传播时的速度。如果波阵面与检波器排列的夹角为θ，设真速度为V，则视速度为V/cos θ。2. 折射波时距曲线斜率的倒数。

apparent wavelength:The distance between corresponding points on successive cycles of a wave train as seen by a geophone spread. Differs from actual wavelength if the wave train direction

makes an angle with the spread.

视波长：在检波器排列方向上，波列两相邻周期相应的波峰或波谷之间的距离。如果波传播方向与检波器排列方向有一夹角，则与真实波长不同。

arrival:An event; a lineup of coherent energy signifying the arrival of a new wavetrain.

波至：波至；表示一个新的波列到达的一组相关能量。arrival time: 1. The time from shot or other energy release to the time which is picked for an event, making allowance for static and dynamic corrections. 2. The time of an event without corrections.

波至时间：1. 从爆炸或其它能量释放后，到拾取到第一个波至之间的时间，它可用于静校正和动校正。2. 未经校正的波至到达时间。

attenuation:1.A reduction in amplitude or energy, such as might be produced by passage through a filter. 2. A reduction in the amplitude of seismic waves, such as produced by divergence, reflection and scattering, and absorption.3.That portion of the decrease in seismic or sonar signal strength with distance not dependent on geometrical spreading. This decrease depends on the physical characteristics of the transmitting media, involving reflection, scattering, and absorption. 4. If the amplitude of a

plane wave is reduced by the factor e-α(f)x in traveling a distance of x meters, then the attenuation factor isα(f). Often thought to be linear with frequency, sometimes thought to be

quadratic with frequency. 5.Regarding the rapid attenuation of electromagnetic waves in the earth, see skin depth.

衰减：1.振幅或能量的减少，例如信号通过滤波器后就有可能发生衰减。2.地震波振幅的减少，由地震波的扩散、反射和散射、及吸收等所致。3.地震或声纳信号强度随传播距离的增大而产生的部分减弱，与信号的几何分布无关，主要依赖于传播介质的物理性质，包括反射、散射和吸收。4.如果

一个平面波传播x米所产生的衰减为e-α(f)x，则衰减因子为α(f)。通常认为衰减与频率成正比，也有人认为与频率的二次方成正比。5.关于电磁波在地下迅速衰减，见趋肤深度。average velocity: The distance traversed by a seismic wavelet divided by the time required, both often corrected to a reference datum plane. For reflections, often refers to a ray reflected at normal incidence.

平均速度：一个地震子波传播距离与所需时间的比值，其中距离和时间通常都被校正到一个参考基准面上。对于反射波来说，常指法线反射路径。

azimuth: The horizontal angle usually specified clockwise from true north.

方位角：通常指由真北按顺时针方向指定的水平角。binary gain:A gain-control system in which amplification is changed only in discrete steps by factors of 2. The times at which the gain steps occur is recorded so that the amplitude can be recovered later.

二进制增益：放大倍数按2的阶次离散变化的增益控制系

统。在增益阶处的时间被记录下来以便以后进行振幅恢复。blind zone: 1. A layer which cannot be detected by refraction methods, also called hidden layer. The blind zone (a) may have a velocity lower than that of shallower refractors, in which case it will lead to an overestimate of the depth of deeper refractors, or it (b) may have a velocity intermediate between those of layers above and below but not have sufficient velocity difference or thickness to produce first-arrivals; in this case it is apt to cause an underestimate at the depth of deeper refractors. 2. A zone from which reflections do not occur; a shadow zone. 3. A zone from which no drill cuttings are returned to the surface. 4. A portion of a formation in which a logging tool response is too low. A blind zone occurs because of the finite size or configuration of the logging tool. For the lateral curve a blind zone (abnormally low reading) is recorded when a bed which is highly resistive compared to the overlying and underlying formations is present between current and measuring electrodes. 5. A layer which cannot be detected by electrical methods because its resistivity is not sufficiently different from the resistivity of other layers or because it is too thin.

盲区：1. 用折射波法无法检测到的区，也称隐蔽层。盲区中(a) 速度低于更浅的折射层速度，这将会导致对更深折射层的深度估计偏大，或者(b) 盲区中速度介于其上面和下面的折射层之间，但二者之间没有足够的厚度或速度差来产生初至，这种情况下容易对更深折射层的深度估计偏小。2.不产生反射的区域；阴影带。3.无钻井岩屑返回地表的区域。4.测井

仪响应很低的岩层。这种盲区的出现主要与测井仪的大小和结构有关。对于梯度电极系测井曲线，当供电电极和测量电极之间出现比其上和其下岩层具有较高阻抗的地层时，该盲区（曲线上反常的低读数）就被记录下来。5.用电法无法检测到的层，这是因为它的电阻率与其它层之间没有明显的差异或者是因为它太薄。

body waves: P- and S-waves which travel through the body of a medium, as opposed to surface waves. See P-wave and S-wave. 体波：在介质体中传播的P- 波和S-波，是相对于面波而言的。参见P- 波和S-波。

break: Onset of an event, especially the first break. A burst of energy indicating the arrival of new energy. see time break and uphole time.

波跳：波列的前端，尤其指初至。能量的突然增大意味着新的能量的到达。参见起爆时间和〔初至波到达〕井口时间buried focus effect:A situation where the concave upward curvature of a reflector is large enough that the energy focuses before it reaches the recording plane. A buried focus situation causes several branches (usually three) of a reflection to be observable from the same surface location (i.e., the law of reflection is satisfied for several points on the reflector from the same surface location). The portion which passes through the focus is called the reverse branch. For zero offset and constant velocity, a buried focus occurs if the center of curvature lies beneath the recording plane. Less curvature is required to produce the buried-focus effect for offset traces than for traces at

normal incidence. Hence buried-focus effects are more likely on long offset traces as well as more likely deeper in the section. velocity gradients and curvature of isovelocity surfaces (which are opt to occur in structural areas) also affect buried-focus effects. Curvature of the reflector out of the plane of the seismic line can also cause multiple branches. There is a quarter-wave phase shift in the reverse branch.

地下焦点效应：当向上凹的反射界面曲率足够大时，使反射能量在到达记录平面之前而聚焦的一种情况。在这种情况下，可观测到来自同一界面位置反射的多个分支（通常三条）（也就是说，反射定律满足同一反射面上多个反射点）。通过焦点的部分称之为回转波。对于零偏移和常速度情况，如果曲率中心位于记录面之下，则会形成地下焦点。非零偏移距记录道产生地下焦点效应比法线入射记录道所需的曲率要小。因此偏移距越大地下聚焦效应表现在剖面上越深。速度梯度和等速面曲率对地下焦点效应也有影响。地震测线平面外弯曲的反射界面也会造成反射的多分支现象。在回转波中存在四分之一个相移。

cable: 1. The assembly of electrical conductors used to connect the geophone or hydrophone groups to the recording truck. See also streamer. 2.The assembly of electrical connectors and tensile members used to support a logging sonde or well geophone or bird.

电缆：1.用来连接地震检波器或水听器组和记录车的导电体组合。见等浮电缆。2.用来支持测井电极系或井中检波器或水鸟的导电体和抗拉张体组合。

chirp:A Vibroseis signal; a sinusoidal signal of continuously varying frequency. often implies a linear change of frequency with time.

线性调频脉冲:一种可控震源信号；一组频率随时间连续线性变化的正弦信号。

coefficient of anisotropy: See anisotropy. V ariation of a physical property depending on the direction in which it is measured.

各向异性系数：见各向异性。物理性质随着被测量的方向而变化。

coherence: l. The property of two wave trains being in-phase. 2.

A measure of the similarity of two functions or portions of functions. If the functions have power spectra P ii and P jj and cross-power spectra P ij (which may complex), their coherence is

P ij/( P ii P jj)1/2

Also called coefficient of coherence. Coherence is the frequency-domain concept which is analogous to correlation in the time domain.

相干性：1. 两波列相位之间的属性。2.两函数或它们的一部分之间的相似性。如果两函数的功率谱分别为P ii和P jj，它们的互功率谱为P ij（可能是复数），则相关性为

P ij/( P ii P jj)1/2

也称之为相关系数。这里的相关性是频率域中的概念，它与时间域相关类似。

coherent:Having a fixed-phase relationship with respect to each other. A set of wave forms is coherent if the phase change

from one to the next has a well-defined relationship. For example, seismic reflection events are coherent in a linear way with respect to dip, coherent in a hyperbolic way with respect to normal moveout, coherent with respect to weathering variations in a nonanalytic though systematic way with respect to geophone locations. The principal evidence for a separate seismic event is coherence among the members of a set of seismic traces over a short time interval of the order of 1-1 /2 or so cycles of the dominant frequency compared with less coherence elsewhere. Coherence is often measured in a qualitative way in record picking but quantitative measures of coherence are used in automatic picking scheme; see semblance. Coherence is used in connection with various types of wave trains, including electromagnetic and seismic waves.

相关的：两者之间存在着固定的相位关系。一组波形如果相位从一种形式变成另一种形式且有明确的关系，则说明这组波形是相关的。例如，地震波反射同相轴与倾角线性相关，与正常时差双曲相关，与风化层变化非解析相关，与检波器位置系统相关。一地震波组中单个地震波相位与该组波相关的主要依据是与其它相关性差的地方相比它们之间有一很短的时间间隔约为1-1 /2个主频周期。相关性在记录拾取中是定性测量的，而在自动拾取中是定量测量的；见相似性。相关性常用于把各种不同类型的波联系起来，包括电磁波和地震波。

common-depth-point:l.The situation where the same portion of the subsurface is involved in producing reflections at

different offset distances on several profiles. 2. Common-depth-point shooting produces redundant reflection data from which a common-depth-point stack can be made. Different shotpoint-geophone combinations are used to record the same reflection from the same subsurface. Also call roll-along. Abbreviated CDP and CRP.

共深度点：1.在几条测线上以不同偏移距产生反射的地下同一点。2. 共深度点爆炸产生冗余的反射数据从而可进行共深度点叠加。不同的炮点检波器组合用来记录来地下自同一反射面的同一反射波。也称逐点爆炸法。缩写为CDP 和CRP。common-depth-point stack: A sum of traces which correspond to the same subsurface reflection point but which are from different profiles and have different offset distances. The traces are corrected for statics and normal moveout before summing (or stacking). The objective is to attenuate random effects and events whose dependence on offset is different from that of normal moveout for primary reflections. Hence multiple reflections which show a different NMO, surface waves, refractions, diffractions, etc., will be attenuated relative to primary reflections. Also called roll-along and horizontal stacking. Petty Geophysical Engineering Company patent.

共深度点叠加：相应于对地下同一反射点的地震道的相加，但它们来自不同测线且具有不同偏移距。这些道在叠加之前都已经过静校正和正常时差校正。其目的就是衰减随机影响和那些与一次反射波随偏移距的正常时差不同的波至。因此，正常时差不同的多次反射波、面波、折射波、绕射波等相对

于一次反射波来说都会被削弱。也称逐点爆炸和水平叠加。佩蒂地球物理工程公司专利。

common-offset gather: A side-by-side display of traces which have the same shot-to-geophone distance (offset).

共偏移距道集：具有相同炮检距的道显示。

common-offset stack: A stack of traces which have the same offset and which are located within a limited range of depth-point locations.

共炮检距叠加（同距叠加）：限定的深度点位置范围内的且炮检距相同的地震道的叠加。

common-range gather: Common-offset gather.

共炮检距道集（选排）：同偏移距道集（选排）。Common reflection point: Common-depth-point.

共反射点：共深度点。

compressional wave: An elastic body wave in which particle motion is in the direction of propagation; the type of seismic wave assumed in conventional seismic exploration. Also call P-wave, dilatational wave, and longitudinal wave.

压缩波：质点运动方向与波传播方向相同的一种弹性体波；常规地震勘探中一种假设的地震波类型。也称为P-波、膨胀波和纵波。

configuration:Arrangement (as of geophones in a group); array.

排列形式：排列（检波器组合）；阵列。

converted wave: Seismic energy which has traveled partly as a P-wave (longitudinal wave) and partly as an S-wave (shear

wave), being converted from one form to the other upon reflection or refraction at oblique incidence on an interface. Since mode conversion is small for small incident angles, converted waves become more prominent as offset increases.

转换波：部分以P-波（纵波）和S-波（剪切波）形式传播的地震波倾斜入射到某一界面上经反射或折射，从一种形式转换成另一种形式。在小入射角情况下转换能量小，随着炮检距的增加，转换波变得更为显著。

critical angle:Angle of incidence θc for which the refracted ray grazes the surface of contact between two media (of velocities V1 and V2):

sin θc = V1 / V2.

临界角：当折射线与两介质的分界面（界面速度分别为V1和V2）相切时，所需的入射角θc：sin θc = V1 / V2. critical reflection: A reflection at the critical angle. Amplitude may be exceptionally large in this vicinity.

临界反射：入射角为临界角时的反射。这时的反射波振幅最大。

curved path: A seismic raypath which is curved because refraction changes the direction of the ray as the velocity changes with depth. Increase in velocity with depth makes the raypath concave upward.

弯曲射线路径：由于速度随深度的变化使得折射方向也随之改变，从而得到一个弯曲的地震射线路径。速度随深度增加，使得射线路径向上弯曲。

deconvolution:The process of undoing the effect of another

filter. Usually an inverse filter is designed and convolved with the signal, the objective being to nullify an objectionable effect of an earlier filter action.

反褶积：解除一个滤波器所带来的影响的过程。通常是设计一个逆滤波器，然后与信号进行褶积，目的是使以前的滤波器对信号的影响变为零。

deep seismic sounding: DSS.

深地震测深：DSS

diffraction: 1. A phenomenon common to all waves(light waves, radio waves, seismic waves, surface water waves, etc.). See Huygens principle. 2.Scattered seismic energy which emanates from an abrupt discontinuity of rock type, particularly common where faults cut reflecting interfaces.

绕射：1.一切波（光波、无线电波、地震波、水面波等）都会出现的一种现象。参见惠更斯原理。2.来自岩性突变处，尤其是来自断层反射面处的散射地震能量。

diffraction stack:A weighted stack of all the elements of reflected energy along a diffraction curve which yields a migrated section (to the extent that the data were two-dimensional). A method of automatically migrating reflection seismic data.

绕射叠加：沿绕射曲线所有反射能量的加权叠加从而得到一个偏移剖面（如果数据是二维的）。是一种自动偏移反射地震资料的方法。

dilatational wave: P-wave.

膨胀波：P-波。

dispersion:1. Distortion of the shape of a wave train because

of the variation of velocity with frequency. The peaks and troughs may advance toward (or recede from) the beginning of the wave as it travels. Leads to the separation of group velocity u from phase velocity v. Where λ = wavelength and f = frequency,

v = f/(1 /λ)

u = df/d (1 /λ).

The dispersion of seismic body waves is very small under most circumstances, but surface waves may show appreciable dispersion in the presence of near-surface velocity layering. The dispersion of electromagnetic body waves is large in most earth materials. 2. A statistical term for the amount of deviation of a value from the norm.

扩散，频散：由于速度随频率的变化使得波列形态发生畸变。在传播过程中波峰和波谷相对于波端可能超前或后退。从而导致群速度u与相速度v彼此分开。v = f/(1 /λ)，u = df/d (1 /λ).其中λ为波长，f为频率。多数情况下，地震体波频散非常小，但是面波在近地表速度层的频散是非常明显的。电磁体波在多数土质材料中扩散是非常大的。2. 计算偏离标准值程度的一个统计学术语。

display: A graphic representation of data, especially of seismic data. The historic display mode for seismic records graphs amplitude as a function of time for each geophone group output, giving wiggle trace or squiggle or conventional display. Variable area display in which the area under the wiggle trace is shaded (often involving a bias and trace clipping) has the advantage that coherent events are more evident. Variable density has also been

used but requires very careful processing to retain a full spectrum of gray shades. Superimposed modes or combined model which involve the use of both wiggle trace and variable area or variable density simultaneously retain many of the good features of each type display. Other display modes are also used.

显示：数据资料特别是地震资料的图形显示。以前的地震记录图形显示方式是把每一组检波器的输出振幅作为时间的函数，给出波形道或波形曲线或常规显示。变面积显示是把波形道下的区域涂上阴影（通常加斜线和修饰线），这样就使相干同相轴显得更突出。变密度显示也是常被用到的，但它需要细心的处理来保留一个完整的灰色阴影频谱。叠加或组合的显示方式就是综合使用波形曲线和变面积或变密度两种方法，使得显示同时保留各种方式各自的优点。另外还有一些其它的显示方式。

diving waves:Refraction in a strong velocity-gradient zone may reverse the component of seismic rays in the downward direction and return them to the surface, where they may be observed (at offset ) as refraction arrivals even though they have no appreciable path through a distinctive refractor. If there are no velocity reversals, diving waves may be used to derive the velocity distribution by means of the Wiechert-Herglotz intergral. 弓形射线波：强速度-梯度带中的折射波，使得向下传播的地震射线分量方向发生逆转并返回地表，且可能被看作折射波波至，尽管它们不是来自一个明显的折射层也没有明显的折射路径。如果没有速度逆转弓形射线波可以通维歇特-赫格劳兹积分求出速度分布。

Dix formula: For reflections from a sequence of flat, parallel layers, the velocity in the n th layer v n (interval velocity) is given by

)()(112122---++=n n n n n n n t t t v t v v where 1-n v and n v are the average velocities from the datum to reflectors above and below the layer and t n-1 and t n are reflection arrival times. This formula, is sometimes misused to calculate interval velocities in situations which do not satisfy Dix's assumptions.

Dix 公式：对于来自水平层状介质的反射波，第n 层的速度v n （层速度）由式：

)()(112122---++=n n n n n n n t t t v t v v 给出，其中1-n v 和 n v 为从基准面到反射层的上一层和下一层的平均速度，t n-1 和 t n 是反射波到达时间。这一公式有时在不满足迪克斯（Dix ）假设的情况下常被误用来计算层速度。 DSS: Deep seismic sounding; a long explosion seismic profile (usually refraction) which has the objective of studying the crust, Moho, and upper mantle.

深地震测深：深层地震测深，一个很长的爆炸地震剖面（通常是折射剖面），其目的是为了研究地壳、莫霍面和上地幔。 dynamic corrections: Normal-moveout correction or corrections which depend on record time.

动校正：正常时差校正或根据记录时间所进行的校正。earthquake:Sudden movement of the earth resulting from faulting or volcanism. An earthquake is classified according to the depth of its focus or hypocenter: shallow < 60 km, intermediate < 300 km, deep > 300 km (sometimes > 450 km). The seismicity of an area is its likelihood of having earthquakes. Some of the energy released in an earthquake is radiated as seismic energy.

天然地震：地球的突然震动，其结果是导致断裂运动或火山活动。天然地震根据震中或震源的深度进行分类：浅层< 60 km，中层< 300 km，深层> 300 km (有时> 450 km)。某一地区的地震活动性就是该地区将要发生地震的可能性。天然地震所释放的部分能量也可被人工地震所利用。earthquake seismology: Study of earthquakes and their resulting seismic waves as a means of understanding the structure of the earth. A schematic seismic record showing several of the wave arrivals from an earthquake is shown in Figure 65. The scheme for identifying different arrivals is discussed under wave notation. Different types of waves may be detected at different distances. The time intervals between different arrivals depends on the distance from the earthquake hypocenter to the observing station. Intensity is a measure of the ground motion at a specific locality; magnitude is a measure of the energy released in the earthquake.

天然地震测震学：对天然地震和其地震波进行研究从而进一步了解地球的内部结构。地震记录示意图如图65所示它可

得到几个不同的波至。图中采用不同的震波符号来标识不同的波至。在不同的位置上可检测到不同类型的波。不同波至间的时间间隔取决于从震中到观测站之间的距离。地震烈度是某一区域地面运动的量度，地震震级则是地震所释放能量大小的量度。

elastic:Returning to its original shape after removal of distorting stress. The return of shape is complete and almost instantaneous rather than gradual.

弹性的：在去除应力后，物体还能恢复原状的一种性质。物体形状的恢复是完全的而且几乎是瞬时的，而不是逐渐恢复原状。

elastic constants:Elasticity deals with deformations that vanish entirely upon removal of the stresses which cause them. The passage of a seismic wave is an example. The general elasticity tensor relating stress and strain in anisotropic media possesses 21 independent constants. In transversely isotropic media in which properties are the same measured in two orthogonal directions, these reduce to five independent constants. Isotropic media (properties the same measured in any direction) have only two independent elastic constants. For small deformations, Hooke's law holds and strain is proportional to stress. The elastic properties of isotropic materials which obey Hooke's law are specified by elastic moduli. These include the following: a.Bulk modulus k: The stress-strain ratio under simple hydrostatic pressure: