body waves and surface waves pdf

In view of its advantage during the study of the 2004 Sumatra-Andaman island earthquake (Ammon et al., 2005), we had developed a quick algorithm to routinely monitor global large earth-quakes by joint inverting body and surface waves. then constrained using both broadband body waves and long period seismic waves. kinds of body waves, and two kinds of surface waves. 15 0 obj << $��獶!��az�s�[?zbr�Ǧ��D�Xރ�A�P��\��Q�,��W ��ɶ;?��$*"b}�Rt�䢌�s��;��:$o,�HH ��?Gf��eb��E"��eL�6�($K�8k|��[.-n�(�Xn`�.^��ί��-pxs1e)��|��C�d�P�ȱP ��,*��%�1��+�%��뇼��#Y�c�� s&"Wd�0\��94B#�O��M63�c��6V �a��܁��=!��E�(�rZ��e�.��G�wd� ��Cbv�y@��cK��dh�#��g6��)�du��(�� `�C�dC�x�N�o �^B formulation used for body waves, except that the surface wave ‘‘ray’’ has a sensitivity that is very wide in depth (Figure 1). >> endobj /Contents 19 0 R Surface waves are typically generated when the source of the earthquake is close to the Earth’s surface. /Resources 49 0 R stream /Annots [ 20 0 R 21 0 R 22 0 R 23 0 R 24 0 R 25 0 R 26 0 R 27 0 R 28 0 R 29 0 R 30 0 R 31 0 R 32 0 R 33 0 R 34 0 R 35 0 R 36 0 R 37 0 R 38 0 R 39 0 R ] stream x��P(�� endstream /Length 15 /Type /XObject When an earthquake occurs, some of the energy it releases is turned into heat within the earth. stream As they spread out, they alternately push (compress) and pull (expand) the ground as they move through it. /Resources 48 0 R <> /Length 8 Some of the energy is expended in breaking and permanently deforming the rocks and minerals along the fault. << /S /GoTo /D [12 0 R /Fit ] >> A general Our preferred model, which based on the MDC fault plane, local JMA hypocenter and calibrated alignments of body and surface waves, revealed a complex rupture process. Much of the motivation for joint inversion derives from two factors. At longer lapse-time, the surface waves couple with body waves and the coda eventually reaches an equipartition regime when all the propagative surface and body wave modes are excited to equal energy (Weaver 1982; Hennino et al. �a�r�$�^��l��vVic�Owo?gʧ��1Sv��YJ�D��vT�n5��&�=�"]6�bO �s7�@�$ ��H��P�%9�j�$��I�|�[o�w��(�]�Ӿ�2��}��[׵��H^��h�\ �7W 2��~��/��d�~��m��ȬW�e��hq��L��L��n��u��vQ��]�,��F'��s��ǄZiqH�cH�{��N��q:)��{�?��Sendstream Body waves Introduction P- and S-waves are referred to as body waves because they are transmitted through the volume (or body) of the material, as apposed to travelling along the surface. endobj %PDF-1.5 P WAVES The … These waves are of a higher frequency than surface waves. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. /Resources 50 0 R This type of seismic body wave travels at the greatest velocity through the ground. 50 0 obj << t�5�O�n�(�Te��m!4「"]�Uͫ��)�e*�j��bW�Ձ��=��c/�]J��ħ]�T��/ݤ��G�*�U��J�R��!RQ�Ń�E�p��$xi�ZiP��$�'}2d^��XԀVW)�Q�n0芊�:��o��l��VnB�GZ�҇�KZ�N��.�1l0 Ҫ�� lC#��~�4[Nj�%.� h��#�+4�C��h�F�{:�%j�� ߡݞ��@#z�#�h��q#-h�S��`�H��ң1�іq��̶]]%�∲@�Y�m�%u��6-T�oj¡�ᒁ��uTt�5v6P9�rLWY�}9/��Ui�pԘ.��AҨ�F��"R�]��Q��G�?��OHuxD�N�qa�� na��ަ��īc��J�07�wG��t��}!6�Je��x�-#P=��"x��N��>>C�� ,a_��C. �&��Vc`�l)S��0@eT�,\L\YsE�ڼ�z��%��x�#��_;_iO��� 2001). >> Surfaces wave energy (amplitudes) decay with distance as 1 / r Body wave energy decays as 1 / r2 So at a given distance, which will have more energy ? x��ZYo�F~7��!�}� ��#�,6X��b��Lˊe�#ʞ��ߪ�"%e`�0�}TWW}�U5��w߽��/��"I��췫��w�'��sU&�w�g,)��%��E!�JTy%��G��U�,��"Y�Sm�~>?��~�owIV�?n�L��U��t�?.��}�:��\��#,�K��k�J��}N��o��Il��T��e��W�D�A��lV��0O��l&��_��'>�S2��2Uc��o��`q��]�DzOg�Hu�� A��@}�4j�U��'�v�f"}6��n�Q�7q�`]�B�n�� A body wave is a seismic wave that moves through the interior of the earth, as opposed to surface waves that travel near the earth's surface. Real-time analysis of earthquakes can be P- and S- waves are called \"body waves\" because they can travel through th… Seismic waves fall into two general categories: body waves (P-waves and S-waves), which travel through the interior of the earth, and surface waves, which travel only at the earth’s … It pushes and pulls the rock it moves through just like sound waves push and pull the air. /R7 53 0 R Waves propagate out from the epicenter along the surface on a three-dimensional view of the earth. Surface waves on the Seismogram Surface waves are the largest amplitude signal on the wave train Surfaces arrive after the P and S waves, because they travel along the surface layers of the Earth where velocities are lower. /BBox [0 0 16 16] /BBox [0 0 362.8347 272.1261] ��٘�M��׎&M'Q�%ȵ�v8��.>��0��Z� iqH�ȕ�m�[>�Ѱ��j�t�֨��(�)�v��(H��k�&��a /ProcSet [ /PDF ] P-waves are able to travel through both sol… 47 0 obj << stream �;f e1�2�j�!P��b�m'dq)��k��RH��b�x�:A�G�s"8M3͓�Cg As a longitudinal compressional waveform, P-waves move in the same way as sound waves. /Resources 47 0 R –No flow through an impervious boundary or body. Surface waves Introduction As a result of geometric spreading in 2-D, the energy carried by surface waves decays with distance r from the source as 1/r; this is in contrast to 1/r2 for body waves, which is why they are usually much less prominent on a seismogram. >> /Filter /FlateDecode The rupture initiated slowly at a depth of 23 km. /Length 1396 /Resources 18 0 R The rest of the energy, which is most of the energy, is radiated from the focus of the earthquake in the form of seismic waves. /Filter /FlateDecode /ExtGState << earthquake; these are body waves and surface waves. /Shading << /Sh << /ShadingType 3 /ColorSpace /DeviceRGB /Domain [0.0 3.99998] /Coords [3.99998 3.99998 0.0 3.99998 3.99998 3.99998] /Function << /FunctionType 3 /Domain [0.0 3.99998] /Functions [ << /FunctionType 2 /Domain [0.0 3.99998] /C0 [0.4375 0.375 0.3125] /C1 [0.875 0.75 0.625] /N 1 >> ] /Bounds [] /Encode [0 1 ] >> /Extend [true false] >> >> • Surface waves propagate along a boundary surface. : 48–50: 56–57 Other modes of wave propagation exist than those described in this article; though of comparatively minor importance for earth-borne waves, they are important in the case of asteroseismology. Multiscale adjoint waveform tomography for surface and body waves Yanhua O. Yuan 1, Frederik J. Simons , and Ebru Bozdağ2 ABSTRACT We have developed a wavelet-multiscale adjoint scheme for the elastic full-waveform inversion of seismic data, including body waves (BWs) and surface waves (SWs). As you might imagine, only body waves can give us any information about the deep interior of the Earth. x� endstream 14 0 obj << endobj >> endobj /Length 15 This generally causes the worst damage because the wave motion rocks the foundations of manmade structures. 49 0 obj << endobj >> endobj /FormType 1 Recent forays into the joint inversion of surface waves and body waves from portable arrays (e.g., Friederich, 2003; van der Lee et al., 2001b; West et al., 2004a), are mostly in an embryonic stage, but hold promise of major improvements in imaging with further development. As their name suggests, surface waves travel just below the surface of the ground. t�=�}��`457�G�Q�D A. P and S waves are body waves. @QW�N�;:r��g�w��V��K#�i�Z��K,z��K쌗��Y�Vr��ܹ��%�$��آ��>�w�:L��fm�M�2��w��r�Gn��8a��jZ'N��&�m��1X��l��S��\��l�H��~��ZR?T� �Y�a The advantage of this method over others using body waves is that it is very rapid and does not require manual intervention, so that it can be made into an automatic process suitable for real-time purposes. waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Surface waves are the slowest moving of all waves, so the most intense shaking usually comes at the end of an earthquake. >> BODY WAVES Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. /Type /XObject >> endobj forward and back-scattered surface waves; and (3) body-to-surface scattered waves (Figure 1). At the same time viewer can watch waves propagating through a cross-sectional view of the earth. Introduction. S��W��ut�R�y��"��buXEh�}�촴kF�숟C�F��pGNF��Y��`. endobj Free Surface Water Waves z x y y=h(x,y,t) or F(x,y,z,t) = 0 B(x,y,z,t) = 0 Figure 1. waves together to the ﬁnite fault source study. /FormType 1 the surface of the Earth). >> endobj From the point of view of the spatial concentration of energy, waves can be divided into body waves and surface waves. >> Free surface water wave problem. 10 0 obj << /ProcSet [ /PDF ] >> Body waves travel through the interior of the Earth. Seismic Waves is an on-line program which illustrates . These waves cause shaking that is felt, and cause damage in various ways. /Subtype /Form <>>> (2) Ground strains caused by body and surface waves have been analyzed for original data and its separated body and surface waves. 3 0 obj The solution was updated twice in three days. BY JOHN V. WEHAUSEN and EDMUND V. LAITONE l With 56 Figures. • Surface waves propagate at a speed lower than body waves and are recorded after the P and S waves. /Type /XObject Body waves can propagate into the interior of the corresponding medium, whereas surface waves are concentrated along the surface of the medium. ��5�Z!YV�,U��;��d&�_�@�Azxx��33��o��{�� 篷��?��o�}��z��-��x�i|�>�[�c��~����_�ߎ/��*}��y�s��yh��^�p#��_�g��m��|ϓeW��b��7��R��vy/-}�r��7��VF��w�;�+(3��|��|�y\��^��Aw��뼑7�5u�=o��/��^��K��͏��J9�{;#��0�ϓ��8_��c��@[#O.f��v=/�3�\�z"��W��o��r�sȥ}�yM1��Q{�!c{z�V��g��7��>��c�F�>62�9�ӽ��8�Θü�*�'�N��o�9`s�w��1�\��C_b+7�/��`�@��8�yc��ہ1��y��|��G��lp�$��Zϴ�9�u��g�9ͳG��8[��2��v>�vB�ٽ=��8+L��Q�;6�5�n��@�?�l�cF��덽��s��g��U�ٲ)5̩Չ��c��Г+O0��u��C¢΋��3��\�s>y�ɜ�`?py.~�o؈��?��*@݁��t�ֵ��s��ɸ��,��J��(�4 �wO#��V��꿾��0J:K?��/�w��3��3�z�,�:�Y�. Surface Waves. Body waves are of two types: Primary waves (also called P-waves, or pressure waves) and Secondary waves (S-waves, or shear waves). �1��_��w�[I;��e��\�v�`��^ Types. Those waves that are the most destructive are the surface waves which generally have the strongest vibration. Earthquakes radiate seismic energy as both body and surface waves. fRi6g��ߤ�!�j J�.O��ʈR�� /Length 54 0 R 4 0 obj 17 0 obj << stream Among the many types of seismic waves, one can make a broad distinction between body waves, which travel through the Earth, and surface waves, which travel at the Earth's surface. 11 0 obj /Matrix [1 0 0 1 0 0] 12 0 obj << a. travel more rapidly than body waves b. produce most of the damage to buildings during earthquakes c. are the first waves initially produced in an earthquake d. are the first waves to arrive at a seismograph station after an earthquake ____ 65. persion characteristics of surface waves contained in strong motion data. /MediaBox [0 0 362.8347 272.1261] 19 0 obj << /Trans << /S /R >> /Subtype /Form Two types of surface waves, known as Love waves … speciﬁc energy density of surface and body waves in a medium containing a homogeneous distribution of point scatterers. endobj /Parent 46 0 R /R 22050 16 0 obj << /ProcSet [ /PDF ] Thereby, waves do appear in various forms and differ in their characteristics. >> Seismic waves can be classified into two basic types: body waves which travel through the Earth and surface waves, which travel along the Earth's surface. 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