震源

The result shows that large airgun source excited in reservoir environment is rich in low frequencies (0 Hz), and is effective to produce waves with long-offset and deep crustal penetration.

试验结果表明，大容量气枪震源是具有丰富的10Hz以下低频信号的低频震源，其激发的地震波具有传播距离远，穿透深度深的特点。

The key problem of the transmitted station is to find the suitable artificial seismic source: powerful, green and clear sources. With the development of airgun technique and information theory, it is possible now to obtain the image of a 100 000 km2 in spatial coverage and 40 km in depth by use of the transmitted seismic stations.

建立地震发射台的核心问题是选择合适的人工震源，近年来出现的绿色环保震源，以及现代信息处理技术的发展，使得建立照亮10万km2地区地下结构的地震发射台已经完全是可能的。

A field experiment using large volume airgun source was conducted in an onshore reservoir. The characteristics of the waveform and its propogation has been studied.

利用大容量气枪震源在陆上水库进行地震波激发试验，研究陆上水库环境下激发气枪震源所产生的地震波特征及传播距离。

This project also compared and discussed the research results of OBS and onshore-offshore experiments in nearby areas. The conclusion is that the active airgun source is equivalent to an earthquake of about magnitude 0.5, and the airgun signals can be detected at the maximum distance of only about 250 km, which is not enough for the study of deeper lithospheric structure below the crust. Furthermore, the onboard airgun source and MCS streamer are difficult to operate in the shallow water of reef and island areas.

本项目还分析对比了周边地区海底地震仪探测和海陆联合地震探测的研究成果，发现人工气枪震源约相当于0.5级的天然地震，其信号传播距离最远只有250 km左右，很难探测到地壳以下更深部的岩石圈结构特征，此外船载的气枪震源和多道电缆在岛礁区和浅水区很难开展工作。

The source-initiation unit in the case of an explosive source is likely to be an electric blaster.

震源的起震装置，在爆炸震源的情况下，可能是一个爆炸机。

The foreland basin phase was controlled mainly by the thrust of Qinlin-Dabie orogenic area during later Jurassic and middle Triassic;the rift basin phase is controlled by fault and deasil circumvolving with the change of stressing during Cretaceous and Paleocene,with strong magma activity;and in the depression basin phase the bas...

盆地地壳结构和小震分布及震源机制解显示地震集中在沉降最大的潜江—沔阳凹陷带附近，震源深度优势分布在15 km左右，即盆地基底附近。

Through synthetical analysis of solutions of focal mechanism and the study of crustal deformation observation data, the recent stress field of hypocenters in Fujian and its coastal area has been obtained, which is considered to links up the stress field in Taiwan and Taiwan Strait, and the dominant direction of axis of principal compressive stress is NW-SE.

综合地震震源机制解和地壳形变观测资料的研究，求得福建及其沿海地区现代震源应力场，认为这与台湾地区、台湾海峡应力场相互衔接，主压应力轴优势方位为NW-SE向，力轴仰角较小，应力场近于水平挤压，形变场反映近期福建沿海亦受北两方向，接近与海岸垂直的挤压力。

When 2 events occur within a same focal region and the distance between 2 events is far shorter than the distance between events and the station, the ratio of observed spectral amplitudes of the direct P and S phases is linearly correlated with the ratio of their radiation pattern factors, and radiation pattern factors depend on geometrical property focal mechanisms.

发生在同一震源区的两个地震，当地震之间的距离远小于地震到台站之间的距离时，同一个台站的直达P波、S波零频观测谱值之比与其辐射图型因子之比线性相关，而辐射图型因子取决于震源机制解的几何特性。

The contrast studies of the heat flow and epicenters of the strong earthquakes (886～1998),the distribution of the geotemperature and high accurate data of focal depth (1983～1997)show that the strong earthquakes take place at the geothermal gradient zone in which the thermal stress concentrates, and that the foci are generally located between 100℃ and 600℃ is...

大地热流与强震( 886～ 1998年)震中、地温分布与精度较高的震源深度资料( 1983～ 1997年)的对比研究表明：云南强震主要发生于热应力集中的地热梯级带；震源一般位于 10 0～ 60 0℃等温线间，相当于 3～ 2 5km深度，并密集分布于 2 0 0～ 4 50℃等温线间，即 5～ 2 0km深处。震源深度分布范围可能与地温所引起的地壳脆韧性转变有关

Shallow moonquakes are located at depth of about 50-220 km, they are strong but rare, and with high-frequency. Deep moonquakes are located at the depth of about 700-1150 km, and occur as clusters related with the tidal stress between the Earth and the Moon.

月震按震源深度分布分为浅源月震与深源月震，前者的震源深度大约为50~220km，释放的能量较大但发生次数较少，记录信号以高频成分为主；后者的震源深度大约为700~1150 km，并具丛集性，与潮汐应力有关。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。