Encyclopedia/1. The Cosmos & The Natural World/4. Earth Sciences/01. Oceanography & Marine Geosciences • Curated by Admin Timeline.sg
A timeline of key milestones in seismology and the discovery of Earth's internal layers, from ancient Chinese seismoscopes to modern earthquake early warning systems, highlighting the contributions of Oldham, Mohorovičić, and Inge Lehmann.
Chronological Storyline (40 Milestones)
132 CE
Zhang Heng invents first seismoscope
Chinese polymath Zhang Heng creates the first seismoscope, a bronze urn with pendulum that detects earthquakes from afar. #seismology #history #ancientchina
Zhang Heng invents first seismoscope By Windmemories - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=176246974
1665 CE
Kircher proposes Earth's internal fires
Athanasius Kircher's 'Mundus Subterraneus' suggests earthquakes are caused by subterranean fires, an early naturalistic theory. #seismology #history
Kircher proposes Earth's internal fires By Cornelis Bloemaert - http://www.portraitindex.de/documents/obj/33802643, Public domain, https://commons.wikimedia.org/w/index.php?curid=89213510
Nov 1, 1755 CE
1755 Lisbon earthquake spurs modern seismology
The devastating Lisbon earthquake kills tens of thousands and prompts systematic scientific study, leading to modern seismology. #seismology #history #earthquake
1755 Lisbon earthquake spurs modern seismology By USGS - USGS http://neic.usgs.gov/neis/eq_depot/world/1755_11_01_loc.gif archived at https://web.archive.org/web/20061124075317/http://neic.usgs.gov/neis/eq_depot/world/1755_11_01_loc.gif, Public domain, https://commons.wikimedia.org/w/index.php?curid=33929811
1841 CE
Robert Mallet coins 'seismology'
Irish engineer Robert Mallet coins the term 'seismology' and conducts explosive experiments to study earthquake waves. #seismology #history
Robert Mallet coins 'seismology' By sconosciuto - https://www.dias.ie/category/geo/geo-robertmallet/, Public domain, https://commons.wikimedia.org/w/index.php?curid=56826037
Dec 16, 1857 CE
Great Neapolitan Earthquake study
Robert Mallet's systematic survey of the 1857 Great Neapolitan Earthquake establishes foundational methods in seismology. #seismology #earthquake
Apr 18, 1889 CE
First teleseism recorded by Rebeur-Paschwitz
Ernst von Rebeur-Paschwitz records the first teleseism (distant earthquake) using a horizontal pendulum in Potsdam, detecting a Japanese quake. #seismology #earthquake
First teleseism recorded by Rebeur-Paschwitz By Unknown author - https://www.hist-geo-space-sci.net/10/173/2019/, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=88827250
1897 CE
Wiechert invents inverted pendulum seismograph
Emil Wiechert designs the inverted pendulum seismograph, improving sensitivity and enabling better earthquake recording. #seismology #invention
Wiechert invents inverted pendulum seismograph By Unknown author - Picture from the website of the Instituto Física of the Universidade Federal do Rio de Janeiro (original), Public domain, https://commons.wikimedia.org/w/index.php?curid=1836346
1906 CE
Oldham identifies Earth's core
Richard Dixon Oldham analyzes P and S waves from the 1906 Assam earthquake to infer a liquid core, and estimates its radius. #seismology #geology #earthcore
Oldham identifies Earth's core By Unknown author - Original on Roger Bilham's earthquake-site, Public domain, https://commons.wikimedia.org/w/index.php?curid=1845055
Oct 8, 1909 CE
Mohorovičić discovers crust-mantle boundary
Andrija Mohorovičić detects a seismic discontinuity (Moho) separating the Earth's crust from the mantle using Balkan earthquake data. #seismology #geology #moho
Mohorovičić discovers crust-mantle boundary By Davorka Herak and Marijan Herak - Seismological Research Letters; November/December 2007; v. 78; no. 6; p. 671-674; DOI: 10.1785/gssrl.78.6.671, Copyrighted free use, https://commons.wikimedia.org/w/index.php?curid=9360920
1912 CE
Gutenberg estimates core-mantle boundary depth
Beno Gutenberg calculates the core-mantle boundary at about 2900 km depth, refining Oldham's model. #seismology #geology #earthcore
Gutenberg estimates core-mantle boundary depth By Unknown author - http://www.egu.eu/awards-medals/portrait-beno-gutenberg/European Geosciences Union, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39281902
1926 CE
Jeffreys proposes liquid core
Harold Jeffreys uses seismic data to argue that the Earth's outer core is liquid, explaining S-wave shadow zones. #seismology #geology #earthcore
Jeffreys proposes liquid core By PeterClarke - Own work (Original text: self-made), CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11121332
1935 CE
Richter develops magnitude scale
Charles Richter creates the Richter magnitude scale to quantify earthquake size, a cornerstone of seismology. #seismology #earthquake
1936 CE
Inge Lehmann discovers Earth's inner core
Inge Lehmann uses P-wave reflections from the core to prove the existence of the solid inner core, redefining Earth's structure. #seismology #geology #earthcore #womeninscience
Inge Lehmann discovers Earth's inner core By Even Neuhaus (6.2.1863-20.4.1946) - http://www5.kb.dk/images/billed/2010/okt/billeder/object11164/da/, Public domain, https://commons.wikimedia.org/w/index.php?curid=90160922
1939 CE
Holyoke seismograph station array
The Holyoke array in Massachusetts begins systematic recording of seismic waves, advancing teleseismic studies. #seismology #technology
1948 CE
Benioff develops strain seismograph
Hugo Benioff invents the Benioff seismograph, improving detection of long-period waves and deep earthquakes. #seismology #invention
Benioff develops strain seismograph By Togabi - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=45373615
1954 CE
Wadati identifies deep-focus earthquakes
Kiyoo Wadati discovers deep-focus earthquakes and the Wadati-Benioff zone, linking seismicity to subduction. #seismology #tectonics #japan
Wadati identifies deep-focus earthquakes By Unknown author - Japanese magazine "The Mainichi Graphic, 13 October 1954 issue" published by The Mainichi Newspapers Co.,Ltd., Public domain, https://commons.wikimedia.org/w/index.php?curid=35508339
May 22, 1960 CE
Great Chilean earthquake (Valdivia) largest recorded
A magnitude 9.5 earthquake in Chile triggers tsunamis and prompts global seismological collaboration. #seismology #earthquake #tsunami
Great Chilean earthquake (Valdivia) largest recorded By Pierre St. Amand - NGDC Natural Hazards Slides with Captions Header, Public domain, https://commons.wikimedia.org/w/index.php?curid=630576
1960 CE
Establishment of WWSSN
The World-Wide Standardized Seismograph Network is established to standardize global seismic monitoring, crucial for nuclear test detection. #seismology #technology #global
1961 CE
Project Vela Uniform for nuclear test detection
The US launches Project Vela Uniform to develop a global seismic network for detecting underground nuclear explosions. #seismology #politics #nuclear
Mar 27, 1964 CE
Great Alaska earthquake
The magnitude 9.2 earthquake in Alaska provides key data for understanding subduction zones and tsunami generation. #seismology #earthquake #tsunami
Great Alaska earthquake By U.S. Army - http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20Alaska%20Earthquake%20no.%20144, Public domain, https://commons.wikimedia.org/w/index.php?curid=3901124
1966 CE
Plate tectonics theory confirmed with seismology
Seismic data from the global network provides key evidence for plate tectonics, revolutionizing Earth sciences. #seismology #tectonics #geology
Plate tectonics theory confirmed with seismology By M.Bitton - Own work based on: Hasterok, Derrick (8 June 2022). New maps of global geological provinces and tectonic plates. American Institute of Physics - Phys.org. Retrieved on 27 March 2023., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=130076176
Jul 20, 1969 CE
Apollo seismometers on the Moon
Apollo 11 places a seismometer on the Moon, detecting moonquakes and revealing lunar interior structure. #seismology #space #moon
Apollo seismometers on the Moon By Neil A. Armstrong - https://tothemoon.im-ldi.com/gallery/Apollo/11/7#AS11-40-5903, Public domain, https://commons.wikimedia.org/w/index.php?curid=170640780
Feb 4, 1975 CE
Haicheng earthquake predicted in China
Chinese seismologists successfully predict a magnitude 7.3 earthquake in Haicheng, leading to evacuation and reduced casualties. #seismology #earthquake #prediction #china
Jul 28, 1976 CE
Tangshan earthquake disaster
A magnitude 7.8 earthquake in Tangshan, China, kills about 242,000 people, one of the deadliest in modern history. #seismology #earthquake #disaster
Tangshan earthquake disaster By the National Oceanic and Atmospheric Administration - https://web.archive.org/web/20070813071606/https://www.ngdc.noaa.gov/nndc/struts/results?eq_1=5&t=101634&s=0&d=4&d=44, Public domain, https://commons.wikimedia.org/w/index.php?curid=11008487
1982 CE
Bullen's Earth model refined
Keith Bullen's models of Earth's interior are refined with new seismic data, providing detailed density and velocity profiles. #seismology #geology #earthcore
Sep 19, 1985 CE
Mexico City earthquake
A magnitude 8.0 earthquake strikes near Mexico City, causing massive casualties due to soil amplification, influencing building codes. #seismology #earthquake #disaster
Mexico City earthquake By United States Geological Survey - http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20Celebi,%20M.%20%203ct&SIZE=large, Public domain, https://commons.wikimedia.org/w/index.php?curid=6573465
1987 CE
Supercomputing for seismic tomography
Advancements in supercomputing allow first seismic tomographic images of mantle plumes and subducting slabs. #seismology #technology #tomography
Supercomputing for seismic tomography By Sanne.cottaar - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=64665106
Oct 17, 1989 CE
Loma Prieta earthquake
A magnitude 6.9 earthquake hits San Francisco, highlighting the need for seismic retrofitting and early warning. #seismology #earthquake #california
Loma Prieta earthquake By H.G. Wilshire, U.S. Geological Survey - Photo by H. G. Wilshire for U.S. Geological Survey. High res version on line at : [1] Lower resolution version: Original image here: http://pubs.usgs.gov/dds/dds-29/web_pages/oakland.html, Public domain, https://commons.wikimedia.org/w/index.php?curid=1417555
1991 CE
Seismic tomography reveals mantle plumes
Global seismic tomography models image mantle plumes beneath hotspots like Hawaii and Iceland. #seismology #geology #mantle
Jan 17, 1994 CE
Northridge earthquake
A magnitude 6.7 earthquake in Northridge, California, causes $20 billion in damage, advancing strong-motion seismology. #seismology #earthquake #california
Northridge earthquake By FEMA News Photo - This image is from the FEMA Photo Library (obsolete as of 2019).An archived copy may be found at the Wayback Machine (note: link may be permanently dead, as not all photos were backed up in this way).If the FEMA link is permanently dead, the photo can be found at NARA Access to Archival Databases (only works if photo was taken between 1989 and October 2004), or at City-data.com., Public domain, https://commons.wikimedia.org/w/index.php?curid=8062897
Jan 17, 1995 CE
Great Hanshin earthquake (Kobe)
A magnitude 6.9 earthquake strikes Kobe, Japan, revealing vulnerabilities in infrastructure and spurring research on active faults. #seismology #earthquake #japan
Great Hanshin earthquake (Kobe) By Kobe (神戸市) - Hanshin-Awaji Earthquake "Record of 1.17" (photo code: b059), CC BY 2.1 jp, https://commons.wikimedia.org/w/index.php?curid=37241600
Jan 26, 2001 CE
Bhuj earthquake in India
A magnitude 7.7 earthquake in Gujarat, India, kills over 20,000, highlighting seismic risk in intraplate regions. #seismology #earthquake #india
Bhuj earthquake in India By Gabriel N - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=6430204
Dec 26, 2004 CE
Indian Ocean earthquake and tsunami
A magnitude 9.1 earthquake off Sumatra triggers a deadly tsunami, leading to the establishment of a global tsunami warning system. #seismology #earthquake #tsunami #indianocean
Indian Ocean earthquake and tsunami By U.S. Navy photo by Photographer's Mate 2nd Class Philip A. McDaniel - This image was released by the United States Navy with the ID 050102-N-9593M-040 (next). This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing. العربية ∙ বাংলা ∙ Bahasa Indonesia ∙ Bahaso Jambi ∙ Deutsch ∙ Deutsch (Sie-Form) ∙ English ∙ español ∙ euskara ∙ فارسی ∙ français ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ മലയാളം ∙ Plattdüütsch ∙ Nederlands ∙ polski ∙ پښتو ∙ português ∙ русский ∙ slovenščina ∙ svenska ∙ Türkçe ∙ українська ∙ 简体中文 ∙ 繁體中文 ∙ +/−, Public domain, https://commons.wikimedia.org/w/index.php?curid=8241767
Mar 28, 2005 CE
Sumatra earthquake
A magnitude 8.6 earthquake off Sumatra provides data on stress changes and aftershock sequences. #seismology #earthquake #indonesia
Sumatra earthquake By U.S. Navy photo by Photographer's Mate 2nd Class Jeffrey Russell - This image was released by the United States Navy with the ID 050404-N-6665R-077 (next). This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing. العربية ∙ বাংলা ∙ Bahasa Indonesia ∙ Bahaso Jambi ∙ Deutsch ∙ Deutsch (Sie-Form) ∙ English ∙ español ∙ euskara ∙ فارسی ∙ français ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ മലയാളം ∙ Plattdüütsch ∙ Nederlands ∙ polski ∙ پښتو ∙ português ∙ русский ∙ slovenščina ∙ svenska ∙ Türkçe ∙ українська ∙ 简体中文 ∙ 繁體中文 ∙ +/−, Public domain, https://commons.wikimedia.org/w/index.php?curid=8198118
May 12, 2008 CE
Wenchuan earthquake in China
A magnitude 7.9 earthquake in Sichuan, China, kills over 87,000, prompting research on rupture dynamics and building resilience. #seismology #earthquake #china
Wenchuan earthquake in China By 서울특별시 소방재난본부 - 서울특별시 소방재난본부 최광모, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=40172686
Jan 12, 2010 CE
Haiti earthquake disaster
A magnitude 7.0 earthquake near Port-au-Prince kills hundreds of thousands due to poor construction, emphasizing seismic risk in developing nations. #seismology #earthquake #disaster #haiti
Haiti earthquake disaster By Trocaire from Ireland - DSC_1200 Uploaded by victorgrigas, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=25580984
Mar 11, 2011 CE
Tohoku earthquake and tsunami
A magnitude 9.0 earthquake off Japan triggers a massive tsunami and Fukushima nuclear accident, revolutionizing understanding of megathrusts. #seismology #earthquake #tsunami #japan
Tohoku earthquake and tsunami By U.S. Navy photo - This image was released by the United States Navy with the ID 110312-N-0000X-003 (next). This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing. العربية ∙ বাংলা ∙ Bahasa Indonesia ∙ Bahaso Jambi ∙ Deutsch ∙ Deutsch (Sie-Form) ∙ English ∙ español ∙ euskara ∙ فارسی ∙ français ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ മലയാളം ∙ Plattdüütsch ∙ Nederlands ∙ polski ∙ پښتو ∙ português ∙ русский ∙ slovenščina ∙ svenska ∙ Türkçe ∙ українська ∙ 简体中文 ∙ 繁體中文 ∙ +/−, Public domain, https://commons.wikimedia.org/w/index.php?curid=14585877
Apr 25, 2015 CE
Nepal earthquake
A magnitude 7.8 earthquake in Nepal kills nearly 9,000, accelerating seismic hazard mapping in the Himalayas. #seismology #earthquake #nepal
Nepal earthquake By Hilmi Hacaloğlu - http://www.amerikaninsesi.com/media/photogallery/2739517.html, Public domain, https://commons.wikimedia.org/w/index.php?curid=39846971
2020 CE
ShakeAlert earthquake early warning system operational
The US West Coast's ShakeAlert system goes live, providing seconds of warning for earthquakes. #seismology #technology #earlywarning
ShakeAlert earthquake early warning system operational By USGS - https://www.usgs.gov/media/images/earthquake-early-warning-basics, Public domain, https://commons.wikimedia.org/w/index.php?curid=84764277
Feb 6, 2023 CE
Turkey–Syria earthquake sequence
A magnitude 7.8 and 7.5 earthquake doublet in Turkey and Syria kills over 50,000, highlighting the need for improved building standards and rapid response. #seismology #earthquake #turkey #syria
Turkey–Syria earthquake sequence By Adem - File:Aerial View of the Hatay Province in Turkey (52699004990).jpg File:Aerial View of the Hatay Province in Turkey (52698845489).jpg File:Aleppo after the 7.8 magnitude earthquake centered in Türkiye 3.jpg File:USAID humanitarian assistance and disaster relief efforts for 7.8 magnitude earthquake in Turkiye 7.jpg File:Chinese Blue Sky and Iranian search and rescue teams are in Adıyaman, which was affected by the earthquakes.jpg, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=128895733
