Christopher Xiang Ren

Dr. Christopher Xiang Ren

Los Alamos National Laboratory, Los Alamos, NM, USA

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 February 2020 in Geophysical Research Letters
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Journal Article
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CRChristopher Xiang Ren
Christopher Xiang Ren
APAline Peltier
Aline Peltier
VFV. Ferrazzini
V. Ferrazzini
Bertrand Rouet-LeducBertrand Rouet-Leduc
Bertrand Rouet-Leduc
PJP. A. Johnson
P. A. Johnson
FBF. Brenguier
F. Brenguier
Volcanic tremor is key to our understanding of active magmatic systems, but due to its complexity, there is still a debate concerning its origins and how it can be used to characterize eruptive dynamics. In this study we leverage machine learning techniques using 6 years of continuous seismic data from the Piton de la Fournaise volcano (La Réunion island) to describe specific patterns of seismic signals recorded during eruptions. These results unveil what we interpret as signals associated with various eruptive dynamics of the volcano, including the effusion of a large volume of lava during the August–October 2015 eruption as well as the closing of the eruptive vent during the September–November 2018 eruption. The machine learning workflow we describe can easily be applied to other active volcanoes, potentially leading to an enhanced understanding of the temporal and spatial evolution of volcanic eruptions.

12 July 2019 in Geophysical Research Letters
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Journal Article
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CRChristopher Xiang Ren
Christopher Xiang Ren
ODO. Dorostkar
O. Dorostkar
Bertrand Rouet-LeducBertrand Rouet-Leduc
Bertrand Rouet-Leduc
CHClaudia Hulbert
Claudia Hulbert
DSDominik Strebel
Dominik Strebel
JCJ. Carmeliet
J. Carmeliet
Seismogenic plate boundaries are posited to behave in a similar manner to a densely packed granular medium, where fault and block systems rapidly rearrange the distribution of forces within themselves, as particles do in slowly sheared granular systems. We use machine learning to show that statistical features of velocity signals from individual particles in a simulated sheared granular fault contain information regarding the instantaneous global state of intermittent frictional stick‐slip dynamics. We demonstrate that combining features built from the signals of more particles can improve the accuracy of the global model and discuss the physical basis behind the decrease in error. We show that the statistical features such as median and higher moments of the signals that represent the particle displacement in the direction of shearing are among the best predictive features. Our work provides novel insights into the applications of machine learning in studying frictional processes occurring in geophysical systems.

22 June 2020 in EarthArXiv
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CRChristopher Xiang Ren
Christopher Xiang Ren
CHClaudia Hulbert
Claudia Hulbert
PJPaul Johnson
Paul Johnson
BRBertrand Rouet‐Leduc
Bertrand Rouet‐Leduc
Geophysics has historically been a data-driven field, however in recent years the exponential increase of available data has lead to increased adoption of machine learning techniques and algorithm for analysis, detection and forecasting applications to faulting. This work reviews recent advances in the application of machine learning in the study of fault rupture ranging from the laboratory to Solid Earth.

30 June 2020 in EarthArXiv
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CRChristopher Xiang Ren
Christopher Xiang Ren
CHClaudia Hulbert
Claudia Hulbert
PJPaul Johnson
Paul Johnson
Bertrand Rouet-LeducBertrand Rouet-Leduc
Bertrand Rouet-Leduc

11 August 2022
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EDEmma Clisby Williams Drobina
Emma Clisby Williams Drobina
EMElisabeth Ann Moore
Elisabeth Ann Moore
MGMichael John Grosskopf
Michael John Grosskopf
CRChristopher Xiang Ren
Christopher Xiang Ren
The U.S. Department of Energy's Office of Scientific and Technical Information

15 May 2020 in arXiv
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CRChristopher Xiang Ren
Christopher Xiang Ren
AZAmanda Ziemann
Amanda Ziemann
ADAlice M. S. Durieux
Alice M. S. Durieux
JTJames Theiler
James Theiler
This paper introduces a new method of generating realistic pervasive changes in the context of evaluating the effectiveness of change detection algorithms in controlled settings. The method, a cycle-consistent adversarial network (CycleGAN), requires low quantities of training data to generate realistic changes. Here we show an application of CycleGAN in creating realistic snow-covered scenes of multispectral Sentinel-2 imagery, and demonstrate how these images can be used as a test bed for anomalous change detection algorithms.