Upload
jumadil-putra
View
214
Download
0
Embed Size (px)
Citation preview
7/27/2019 sedi_pengantar
1/60
IntroductionSeismolo and the Earths Dee Interior
Seismologi dan Struktur Bumi
Minggu-ke Topik1 Pengantar Networks Seismisitas
2 Teori Elastisitas
3 Persamaan Gelombang Elastik
4 Quiz
5 Teori Sinar dan Tomografi Seismik
6 Gelombang Permukaan dan Osilasi Bebas
7 Struktur Bumi bagian dalam
8 Quiz
9 Sumber Seismik
10 Seismo-tectonik
11 Scattering Gel. Seismik
12 Quiz
13 TBA
7/27/2019 sedi_pengantar
2/60
IntroductionSeismolo and the Earths Dee Interior
Literatur Text Books
Shearer, Introduction to Seismology, CambridgeUniversity Press, 1990.
Wysession and Stein, An introduction to seismology,earthquakes and earth structure, Blackwell Scientific
Kennett, The Seismic Wavefield, I+II, Cambridge
University Press
Lay and Wallace, Modern Global Seismology, AcademicPress, 1995.
Gubbins, Seismology and Plate Tectonics, Cambridge
University Press, 1990.
Aki and Richards, Quantitative Seismology, AcademicPress, 2002.
Anderson, Theory of the Earth, Blackwell, 1989.
7/27/2019 sedi_pengantar
3/60
Introduction
Pengantar Seismologi
Seismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
4/60
IntroductionSeismolo and the Earths Dee Interior
Sebuah seismogram
7/27/2019 sedi_pengantar
5/60
IntroductionSeismolo and the Earths Dee Interior
Seismologi dan Struktur Bumi
Sejarah Singkat Seismologi
Todays seismicity (live!)SeismometriJejaring Seismik
Gempabumi yang terjadi seduniaDistribusi gempabumiGempa Utama Abad iniSumber gempaKuantifikasi gempa
Struktur Bumi
Struktur secara Spherically symmetricModel 3-D (tomografi seismik)
10 Tantangan Seismologi
7/27/2019 sedi_pengantar
6/60
IntroductionSeismolo and the Earths Dee Interior
History The first seismometer
Seismometer Chang Heng (132 M)
Dengan alat iniarah sumber
gempa apat diprediksi !
7/27/2019 sedi_pengantar
7/60
IntroductionSeismolo and the Earths Dee Interior
History milestones
Di Eropa riset di bidang seismologi berkembangsemenjak kejadian 2 gempa merusak pada abadke 18, yaitu:
1755 gempabumi Lissabon, Portugal, 32000 tewasgempabumi di Calabria, Italy30000 tewas
Experimental seismology Theoretical seismology
1846 Mallet
1880 Milne (first real seismograph)1889 First teleseismic recording
(Potsdam)
1884 Intensity scale (Rossi-Forrel)
1831 Poisson, gelombang pada
medium infinit1849 Stokes, Gel. P dan S sebagai
dilatasi dan gel. shear
1885 Rayleigh, Gel pada mediumsetengah tak hingga, gel. Permukaan
7/27/2019 sedi_pengantar
8/60
IntroductionSeismolo and the Earths Dee Interior
History milestones (contd)
1900 Oldham: identification of P, S, and surfacewaves
1901 Wiechert: first geophysical institute inGttingen, Germany. Development ofseismometers
1903 Foundation of International SeismologicalAssociation
1906 San Francisco earthquake: 1000 killed.
Galitzin seismograph
1909 Mohorovicic discontinuity (MOHO)
1911 Theory of Love waves
Seismological Society of America
7/27/2019 sedi_pengantar
9/60IntroductionSeismolo and the Earths Dee Interior
History milestones (contd)
1913 Determination of radius of Earths core
by Benno Gutenberg (Gttingen)
1923 Tokyo earthquake (Great Japanese Quake)
250000 killed, Foundation of Earthquake ResearchInstitute (ERI)
1903 Foundation of International SeismologicalAssociation
1931
1932
Benioff Seismometer
Strain seismometer
19351936 Richter magnitudeDiscovery of the Earths inner core by IngeLehmann (1888-1993)
1940 Sir Harrold Jeffreys, Cambridge
Traveltime tables. Bullen density model
7/27/2019 sedi_pengantar
10/60IntroductionSeismolo and the Earths Dee Interior
History milestones (after 1950)
1960 Pengamatan osilasi bebas Bumi pasca gempa
besar di Chile 1960
1963 Limited Test Ban Treaty, World WideStandard Seismograph Network (WWSSN)
Late
60s
Konsep tektonik lempeng diakui
1981 Preliminary Reference Earth Model (PREM)
Mid 80s Model tomografi 3-D pertama yang
menunjukan heterogenitas mantel bumi
1997 Rotasi dari inti bumi bagian dalam
7/27/2019 sedi_pengantar
11/60IntroductionSeismolo and the Earths Dee Interior
Monitoring Seismik di Jerman (Sta-FFB)
Rekaman gempabumi selama 24 jamdi Observatorium FFB
7/27/2019 sedi_pengantar
12/60IntroductionSeismolo and the Earths Dee Interior
Seismometer di Indonesia
Distribution seismometers diIndonesia yang dioperasikan
oleh BMKG
7/27/2019 sedi_pengantar
13/60IntroductionSeismolo and the Earths Dee Interior
Gempabumi di Dunia
distribusi gempa sejak 1954-1998 dengan magnitudo >= 4.0NEIC (National Earthquake Information Center)ada lebih dari 240 000 seismic events with magnitude >=4.0
BGR Hannover
7/27/2019 sedi_pengantar
14/60IntroductionSeismolo and the Earths Dee Interior
Gempabumi di Indonesia
7/27/2019 sedi_pengantar
15/60IntroductionSeismolo and the Earths Dee Interior
Gempabumi di Jerman
Earthquakes in Germany
(historical and measured)(BGR Hannover)
7/27/2019 sedi_pengantar
16/60IntroductionSeismolo and the Earths Dee Interior
Statistika Gempabumi
MS Earthquakesper year
---------- -----------8.5 - 8.9 0.38.0 - 8.4 1.17.5 - 7.9 3.17.0 - 7.4 156.5 - 6.9 56
6.0 - 6.4 210
7/27/2019 sedi_pengantar
17/60IntroductionSeismolo and the Earths Dee Interior
The Earthquake - Top Ten Chart
2.) Sumatra-Andaman 26/12/2004 9.3 Mw
3.) Alaska 03/28/1964 9.2 Mw 61.1 N 147.5 W
4.) Russia 11/04/1952 9.0 Mw 52.75 N 159.5 ETohuku 11/03/2011 8,9 Mw Tsunami
5.) Ecuador 01/31/1906 8.8 Mw 1.0 N 81.5 W
6.) Alaska 03/09/1957 8.8 Mw 51.3 N 175.8 W
7.) Kuril Islands 11/06/1958 8.7 Mw 44.4 N 148.6 E
8.) Alaska 02/04/1965 8.7 Mw 51.3 N 178.6 E
9.) India 08/15/1950 8.6 Mw 28.5 N 96.5 E
10.) Argentina 11/11/1922 8.5 Mw 28.5 S 70.0 W
1.) Chile 05/22/1960 9.5 Mw 38.2 S 72.6 W
and the winner is
7/27/2019 sedi_pengantar
18/60IntroductionSeismolo and the Earths Dee Interior
Gempabumi - Top Ten - Map
The ten largest earthquakes this century
7/27/2019 sedi_pengantar
19/60IntroductionSeismolo and the Earths Dee Interior
Seismologi dan Tektonik Lempeng
Tectonic plates on Earth
7/27/2019 sedi_pengantar
20/60IntroductionSeismolo and the Earths Dee Interior
Rekonstruksi gerakan lempeng
7/27/2019 sedi_pengantar
21/60IntroductionSeismolo and the Earths Dee Interior
Konsep Tektonik Lempeng
7/27/2019 sedi_pengantar
22/60IntroductionSeismolo and the Earths Dee Interior
Tektonik Lempeng Mantle Convection
A current issue of debate is whether the Earths mantle convectsas a whole or whether there is layered convection.
Seismology can only provide the present state of the Earthsconvective system!
7/27/2019 sedi_pengantar
23/60IntroductionSeismolo and the Earths Dee Interior
Tektonik Lempeng hot spots
Schematic pictureof the Hawaiian islandchain and the underlying
Hot spot.
The origin of hot spots and their mechanism are still poorly understood.
7/27/2019 sedi_pengantar
24/60IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics hot spots - plumes
7/27/2019 sedi_pengantar
25/60IntroductionSeismolo and the Earths Dee Interior
Tektonik Mid-oceanic ridges
Global ridge system Topography mid-atlantic ridge
Plate motions are up to 15cm per year
7/27/2019 sedi_pengantar
26/60IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Discovery
The proof of plate tectonics came from the magnetization ofthe seafloor as a function of distance from the ridge axes.
7/27/2019 sedi_pengantar
27/60IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Volcanoes
Pinatubo, 1991 Mount St. Helens, 1980
7/27/2019 sedi_pengantar
28/60
IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Volcanoes (contd)
7/27/2019 sedi_pengantar
29/60
IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Fault Zones
San Andreas Fault Fault zones in California
7/27/2019 sedi_pengantar
30/60
IntroductionSeismolo and the Earths Dee Interior
Fault zone waves
Considerable FZtrapped waveenergy generated.
Receivers
l d h
7/27/2019 sedi_pengantar
31/60
IntroductionSeismolo and the Earths Dee Interior
Fault zone structure at depth
New interpretation Previous concept
Shallow LVfeatures
LV featuresextending togreater depth
7/27/2019 sedi_pengantar
32/60
IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Earthquakes
Earthquake damage in California
7/27/2019 sedi_pengantar
33/60
IntroductionSeismolo and the Earths Dee Interior
Plate Tectonics Earthquakes
Seismologist recordingaftershocks in California
7/27/2019 sedi_pengantar
34/60
IntroductionSeismolo and the Earths Dee Interior
Earthquake sources
7/27/2019 sedi_pengantar
35/60
IntroductionSeismolo and the Earths Dee Interior
Mercalli Intensity and Richter MagnitudeMagnitudo Intensitas Diskripsi
1.0-3.0 I I. Tidak dirasakan kecuali oleh orang-orang pada kondisi khusus.
3.0 - 3.9 II - III II. Dirasakan oleh orang yang sedang tiduran, terutama di lantai bangunan.III. Felt quite noticeably by persons indoors, especially on upper floors of buildings.Many people do not recognize it as an earthquake. Standing motor cars may rockslightly. Vibrations similar to the passing of a truck. Duration estimated.
4.0 - 4.9 IV - V IV. Felt indoors by many, outdoors by few during the day. At night, some awakened.Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truckstriking building. Standing motor cars rocked noticeably.V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstableobjects overturned. Pendulum clocks may stop.
5.0 - 5.9 VI - VII VI. Felt by all, many frightened. Some heavy furniture moved; a few instances offallen plaster. Damage slight.VII. Damage negligible in buildings of good design and construction; slight to moderatein well-built ordinary structures; considerable damage in poorly built or badly designedstructures; some chimneys broken.
6.0 - 6.9 VII - IX VIII. Damage slight in specially designed structures; considerable damage in ordinarysubstantial buildings with partial collapse. Damage great in poorly built structures. Fall
of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned.IX. Damage considerable in specially designed structures; well-designed framestructures thrown out of plumb. Damage great in substantial buildings, with partialcollapse. Buildings shifted off foundations.
7.0 andhigher
VIII orhigher
X. Some well-built wooden structures destroyed; most masonry and frame structuresdestroyed with foundations. Rails bent.XI. Few, if any (masonry) structures remain standing. Bridges destroyed. Rails bentgreatly.XII. Damage total. Lines of sight and level are distorted. Objects thrown into the air.
7/27/2019 sedi_pengantar
36/60
IntroductionSeismolo and the Earths Dee Interior
The Earths Deep Interior
7/27/2019 sedi_pengantar
37/60
IntroductionSeismolo and the Earths Dee Interior
The Earths Radial Structure
7/27/2019 sedi_pengantar
38/60
IntroductionSeismolo and the Earths Dee Interior
Traveltimes of Teleseismic Phases
The Earths deep structure isdetermined by inverting thousands ofseismic travel times
-> seismic tomography
7/27/2019 sedi_pengantar
39/60
IntroductionSeismolo and the Earths Dee Interior
3-D tomography
Maybe the mostimportant goal in
global seismology todayis to determinethe Earths global 3-Dstructure withhigh resolution- Source: Harvard
l h ll
7/27/2019 sedi_pengantar
40/60
IntroductionSeismolo and the Earths Dee Interior
Seismology Schematically
Seismic Source
Ruptures, crack propagation,physics of earthquakes,
magnitude, faulting, seismiccreep, radiation pattern,Earthquake precursors,
aftershocks, fault planes, etc.
Propagation Effects
heterogeneities, scattering, attenuation,anisotropy, rays, body waves, surface waves,
free oscillations, reflections, refractions,trapped waves, geometrical spreading, etc.
Seismometer
Filtering, (de)convolution, threecomponents, spectrum, broadband,
strong-motion, tilt, long-period,amplification, etc.
h ll l
7/27/2019 sedi_pengantar
41/60
Introduction
Grand Challenges in Seismology
Seismolo and the Earths Dee Interior
H d f l l
7/27/2019 sedi_pengantar
42/60
Introduction
How do fault slips?
Seismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
43/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
44/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
45/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
46/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
47/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
48/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
49/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
50/60
IntroductionSeismolo and the Earths Dee Interior
7/27/2019 sedi_pengantar
51/60
IntroductionSeismolo and the Earths Dee Interior
Wiechert Pendulum seismometer
7/27/2019 sedi_pengantar
52/60
IntroductionSeismolo and the Earths Dee Interior
Wiechert Pendulum seismometer
The 1000 kg Wiechert invertedpendulum seismograph (after Wiechert,
1904). The plate P is attached to theframe of the instrument. N is attachedto the pendulum mass. The motion ofthe mass relative to the frame isresolved at A into perpendicularcomponents. Restoring force is appliedto the mass M from springs at C, C', bymeans of the rods B, B'. H, H' are thedamping cylinders. The whole invertedpendulum is pivoted at K. In the actualseismometer, the rotation of thependulum about K takes place in flatsprings, which are arranged in a Cardanhinge to permit the pendulum to move inany horizontal direction.
Back to the listModern seismometers
Modern 3 C seismometer
7/27/2019 sedi_pengantar
53/60
IntroductionSeismolo and the Earths Dee Interior
Modern 3-C seismometer
Back to the list
1889 The first teleseismic record
7/27/2019 sedi_pengantar
54/60
IntroductionSeismolo and the Earths Dee Interior
1889 - The first teleseismic record
This seismogram wasrecorded in Potsdam in1889. The seismicwaves were generatedby an earthquake inJapan.
Back to the list
Benno Gutenberg
7/27/2019 sedi_pengantar
55/60
IntroductionSeismolo and the Earths Dee Interior
Benno Gutenberg
Back to list
Charles Richter
7/27/2019 sedi_pengantar
56/60
IntroductionSeismolo and the Earths Dee Interior
Charles Richter
Back to list
Sir Harold Jeffreys
7/27/2019 sedi_pengantar
57/60
IntroductionSeismolo and the Earths Dee Interior
Sir Harold Jeffreys
Back to list
1891-1989
Nuclear Explosions until Today
7/27/2019 sedi_pengantar
58/60
IntroductionSeismolo and the Earths Dee Interior
Nuclear Explosions until Today
Back to list BGR Hannover
Alaska 1964 earthquake
7/27/2019 sedi_pengantar
59/60
IntroductionSeismolo and the Earths Dee Interior
Alaska 1964 earthquake
Back to list
San Francisco earthquake in FFB#
7/27/2019 sedi_pengantar
60/60
San Francisco earthquake in FFB#
Back to the list