The Earth, Planets and Space (EPS) Young Researcher Award

The EPS 2022 EPS Young Researcher award is granted to Dr. Takahiro Abe, as the first author of the following paper.

Surface displacement revealed by L-band InSAR analysis in the Mayya area, Central Yakutia, underlain by continuous permafrost
Takahiro Abe, Go Iwahana, Petr V. Efremov, Alexey R. Desyatkin, Takumi Kawamura, Alexander Fedorov, Yuri Zhegusov, Kazuki Yanagiya and Takeo Tadono
Earth, Planets and Space 2020 72:138

Published on: 22 September 2020

This paper studied the landform deformation caused by the permafrost thawing in Yakutia in eastern Siberia through L-band InSAR data analysis. Such ground deformation response is important to monitor the effects of recent global warming on the Arctic environment. Previous studies on permafrost were mostly based on pointwise onsite measurements. By applying the InSAR stacking technique, the authors successfully revealed the spatiotemporal distribution of the seasonal as well as inter-annual subsidence of a partially forested thermokarst area. With wide coverage and good spatial resolution for the amplitude of the ground deformation related to the degradation of permafrost, this study demonstrated a new application of InSAR technology to the monitoring of permafrost areas. The first author Takahiro Abe has made the main contribution to this study, to whom we award the 2022 EPS Young Researcher Award.

The 2021 EPS Young Research Award is granted to Guillaume Ropp, as the first author of the following paper.

Sequential modelling of the Earth’s core magnetic field
Guillaume Ropp, Vincent Lesur, Julien Baerenzung & Matthias Holschneider
Earth, Planets and Space volume 72, Article number: 153 (2020)

This paper proposed a new original method to estimate the core magnetic field with a better separation of sources contributing to the observed geomagnetic field. The new method combined a sequential modelling approach with Kalman filter, and a correlation-based modelling step. The separation of different contributions relies on a strong prior information on their spatial and temporal behaviours of the geomagnetic field. The new method also yields reliable uncertainties on the core magnetic field and reliably render fast variations of the core field and its secular variation. The new method has a potential to make a great leap forward by modeling core field variations at shorter periods, which will also impact other research fields such as earth rotation. The first author Guillaume Ropp has made the main contribution to this study, to whom we award the 2021 EPS Young Researcher Award.

The 2020 EPS Young Researcher Award is granted to Masaya Kimura, as the first author of the following paper.

Earthquake-induced prompt gravity signals identified in dense array data in Japan
Masaya Kimura, Nobuki Kame, Shingo Watada, Makiko Ohtani, Akito Araya, Yuichi Imanishi, Masaki Ando and Takashi Kunugi
Earth, Planets and Space 2019 71:27,120

This paper reported an observation of transient elastogravity signals prior to the P-wave arrival of the 2011 Tohoku-oki earthquake by using a new processing strategy. They optimized the multi-channel data recorded by superconducting gravimeters, broadband seismometers and tiltmeters, providing new constraints on the amplitude of the observed prompt signals that may serve as a reference in the detection of similar signals in future earthquakes. In this paper, the authors also proposed a theoretical development of the prompt signal as gravity-gradient in addition to acceleration and gravity perturbation. Such elastogravity transient perturbation is promising for future early-warning systems. This paper highlighted scientific interests about this transient gravity signal. The first author Masaya Kimura has made the main contribution to this study, to whom we award the 2020 EPS Young Researcher Award.

The 2019 EPS Young Researcher Award is granted to Shoya Matsuda, as the first author of the following paper.

Onboard software of Plasma Wave Experiment aboard Arase: instrument management and signal processing of Waveform Capture/Onboard Frequency Analyzer
Shoya Matsuda, Yoshiya Kasahara, Hirotsugu Kojima, Yasumasa Kasaba, Satoshi Yagitani, Mitsunori Ozaki, Tomohiko Imachi, Keigo Ishisaka, Atsushi Kumamoto, Fuminori Tsuchiya, Mamoru Ota, Satoshi Kurita, Yoshizumi Miyoshi, Mitsuru Hikishima, Ayako Matsuoka and Iku Shinohara
Earth, Planets and Space volume 70, Article number: 75 (2018)

This paper reports the development of onboard software for the Plasma Wave Experiment (PWE) onboard the Arase satellite. This software was designed to measure DC electric field and plasma waves covering a wide frequency range (DC up to 10 MHz for electric field and a few Hz to 100 kHz for magnetic field). The cutting-edge technologies enable the PWE to successfully obtain important properties (e.g., power spectrum, wave normal direction, and polarization), as well as waveforms of both whistler-mode chorus and ion cyclotron mode waves in the inner magnetosphere. The PWE also has a significant function of providing raw waveform data to the software-type wave-particle interaction analyzer (S-WPIA), which derives direct correlation to the estimation of energy transfer between waves and particles. Data obtained from the PWE are indispensable in determining the detailed properties of plasma waves and wave-particle interaction in the inner magnetosphere and are essential for the success of the Arase mission. The first author, Dr. Shoya Matsuda, has made the most significant contribution to this study. Therefore, we award him the 2019 EPS Young Researcher Award.
 

The 2018 EPS Young Researcher Award is granted to C. H. Chen, as the first author of the following paper.

Medium-scale traveling ionospheric disturbances by three-dimensional ionospheric GPS tomography 
C. H. Chen, A. Saito, C. H. Lin, M. Yamamoto, S. Suzuki and G. K. Seemala, 

In this study, the authors developed a three-dimensional ionospheric tomography using ground-based Global Positioning System (GPS) total electron content (TEC) observations. They evaluated their algorithm using the model ionosphere with Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) and obtained acceptable results. The new design of their algorithm did not use a predefined ionosphere model; instead, they simply used the “least-square” method with a constraint condition to avoid ill-posed problems. This kind of algorithm will be highly useful for the reconstruction of the disturbed ionosphere.

The 2017 EPS Young Researcher Award is granted to Hisashi Hayakawa.

Records of sunspot and aurora during CE 960–1279 in the Chinese chronicle of the Sòng dynasty
Hisashi Hayakawa, Harufumi Tamazawa, Akito Davis Kawamura and Hiroaki Isobe

In this study, records of solar and auroral activities from the 10th to 13th centuries were retrieved from the Chinese chronicle of the Sòng dynasty. The accuracy of these records were tested scientifically through comparison with the 14C contents in tree rings during that period. This is important because it is the first step taken to survey and compile records of sunspots and auroras from historical documents of various regions and in different languages (the authors have also published a paper on historical auroral events using records in the Babylonian astronomical diaries in 2016 EPS), with the ultimate goal of creating an online database for use by scientists studying historical/extreme solar/auroral events and long-term changes in solar/auroral activity. Such a unified dataset with records from various locations and in different languages is the first of its kind, and will therefore be of value to the scientific community.

The 2016 EPS Young Researcher Award is granted to Michiyo Sawai.

Frictional properties of incoming pelagic sediments at the Japan Trench: implications for large slip at a shallow plate boundary during the 2011 Tohoku earthquake
Michiyo Sawai, Takehiro Hirose, Jun Kameda

The slip at the shallow part of the megathrust triggered the destructive Tsunami associated with the Tohoku Earthquake in 2011. Thus, it is important to understand how such a large rupture can take place in sedimentary sequences. Sawai et al. (2014) investigated the dynamic frictional properties of incoming sediment off the Japan Trench. From the experiment with a wide range of coseismic velocities, they found that the friction coefficient is less than 0.2 for a wide range of slip velocities in a smectite-rich zone at the bottom of the sedimentary section, which is equivalent to the fault zone of the Tohoku earthquake. Most importantly, this study showed that the fracture energy of aggregated sediments was by far lower than the ones obtained by the previous experiments using disaggregated sediments. This is an important finding for the generation of shallow rapture. The first author contributed significantly to this excellent study that will be leading a research in a new direction by combining seismological and geological sciences. Thus, Dr. Michiyo Sawai is deserving of the EPS Young Researcher Award 2016.

The 2015 EPS Award is granted to Christoph Püthe.

Determination of the 3-D distribution of electrical conductivity in Earth's mantle from Swarm satellite data: Frequency domain approach based on inversion of induced coefficients
Christoph Püthe and Alexey Kuvshinov

Most previous global induction studies have assumed simple structures of the source field and simplified models of the Earth, using mostly ground-based observations as data. This study presented a new approach to global induction studies using the data from Swarm geomagnetic satellite missions in order to infer the three-dimensional (3-D) conductivity structure of the mantle. The author suggested a consistent way of working with satellite geomagnetic data, the sources of the complex spatial structures, and full 3-D conductivity models. The author not only introduced the concept, but also developed and thoroughly tested a new modeling code to cope with the aforementioned challenges. This study has opened a door to new global induction studies. The first author, Dr. Christoph Püthe, made the most significant contribution to this study. Therefore, we award him the 2015 EPS Award.