Research | Karen Lythgoe | Earth Observatory of Singapore

My research lets me explore our planet’s grandest processes, from the creation of Earth’s very centre to the movements of its fragile crust. I do this using seismology, but rather than using a specific method/data type, I prefer to develop techniques most suitable to answer the scientific questions in hand. My current projects range from assisting urban development in Singapore to working with local institutes to better understand the tectonic processes in more remote areas.

Nodal Arrays

Seismic nodal instruments are revolutionising the acquisition of low cost, high quality seismic data in industry and academia. The instruments facilitate the acquisition of large, dense, seismic surveys in any land environment and have the ability to transform subsurface imaging. This is particularly true in areas where deploying a traditional seismic network is prohibitively expensive or where the environment makes traditional surveys impossible.

SE Asia is one of the least studied and instrumented regions in the world, yet it is vulnerable to many natural hazards and is facing many challenges in terms of urbanisation and sustainable management of resources. The Earth Observatory of Singapore has an inventory of 220 nodes, which we use for rapid response to record aftershocks following large earthquakes and for targeted imaging studies.

Relevant publications:

Ourabah, A., Crosby, A., Brooks, C., Manning, T., Lythgoe, K. H., Ablyazina, D., Zhuzhel, V., Holst, E., Knutsen, T. (2019) ‘A Comparative Field Trial of a New Nimble Node and Cabled Systems in a Desert Environment’, EAGE Conference and Exhibition Extended Abstract, https://doi.org/10.3997/2214-4609.201901136
Lythgoe, K. H., Ong Su Qing, M., & Wei, S. (2020). Large‐scale crustal structure beneath Singapore using receiver functions from a dense urban nodal array. Geophysical Research Letters, 47 https://doi.org/10.1029/2020GL087233s

Volcano-fault interactions and the Lombok earthquake cascade

On 29 July 2018, a Mw 6.4 earthquake struck the northern coast of Lombok, beginning a complex sequence of foreshock, mainshock, and aftershock earthquakes. These earthquakes were produced by rupture of the Flores Thrust, which dips beneath the northern coast of Lombok and intersects the root zone of the active arc volcano Gunung Rinjani. In collaboration with ITB and BMKG in Indonesia, a seismic array was rapidly deployed providing detailed observations of the subsequent large (Mw 6.9) ruptures and their immediate aftershocks.

Relevant publications:

Lythgoe K., Muzli, Bradley K, Wang T, Nugraha ADian, Zulfakriza, Widiyantoro S, Wei S. (2021). Thermal squeezing of the seismogenic zone controlled rupture of the volcano-rooted Flores Thrust. Science Advances. 7(5)
Salman, R., Lindsey, E.O., Lythgoe, K., Bradley, K., Muzli, M., Yun, S.H., Chin, S.T., J. Tay, C.W., Costa, F., Wei, S. and Hill, E.M., (2020). Cascading Partial Rupture of the Flores Thrust during the 2018 Lombok Earthquake Sequence, Indonesia', Seismological Research Letters, 91 (4): 2141–2151. doi: https://doi.org/10.1785/0220190378

Seismic hazard and tectonic structure of Aceh, Sumatra

The Sumatran Fault is one of the world’s largest strike-slip faults, hosting many large earthquakes, however the Sumatran Fault is relatively poorly studied and there are many outstanding questions about how this fault behaves, and its relationship with regional tectonics. Aceh, in the very north of Sumatra, is the most seismically active part of the island and considered to have the highest seismic hazard in the region. This work addresses 1) identifying active fault branches and changes in fault behaviour along the Sumatra Fault, 2) the relationship between the Sumatra Fault, subduction and volcanism. Working with the Tsunami Disaster Research Institute and Syiah Kuala University in Banda Aceh, we have deployed over 100 nodes in Aceh.

Singapore Seismic Survey

Development of the subsurface will form a crucial part of Singapore's future, particularly because of its limited land area and lack of natural resources. In 2019, I designed and executed the first large scale passive seismic survey of Singapore. Results from this survey aim to improve the integration and understanding of subsurface properties, resources, and natural hazards for smart city development.

Relevant publications:

Lythgoe, K., Ong Su Qing, M., & Wei, S. (2020). Large‐scale crustal structure beneath Singapore using receiver functions from a dense urban nodal array. Geophysical Research Letters, 47 https://doi.org/10.1029/2020GL087233s

Structure and dynamics of Earth's inner core

My PhD work was multi-disciplinary, using seismic waves to image the structure of Earth’s inner core and then interpreting this structure in terms of its evolution and dynamics.

Relevant publications:

Lythgoe, K., Inggrid, M. I., Yao, J. (2020) On waveform correlation measurement uncertainty with implications for temporal changes in inner core seismic waves. Physics of the Earth and Planetary Interiors, 309, https://doi.org/10.1016/j.pepi.2020.106606
Lythgoe, K. and A. Deuss (2015) ‘The existence of radial anisotropy in Earth’s upper inner core revealed from seismic normal mode observations’, Geophysical Research Letters, 42, 4841-4848.https://doi.org/10.1002/2015GL064326
Lythgoe, K., Rudge, J. F., Neufeld, J. A., Deuss, A. (2015) 'The feasibility of thermal and compositional convection in Earth’s inner core', Geophysical Journal International. 201, 764–782. https://doi.org/10.1093/gji/ggv034
Lythgoe, K., Deuss, A., Rudge, J. F., Neufeld, J. A. (2014) ‘Earth’s inner core: innermost inner core or hemispherical variations?’ Earth and Planetary Science Letters, 385, 181 – 189. https://doi.org/10.1016/j.epsl.2013.10.049

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Figure reproduced from Physics Today (66, 11, 37, 2013)