Scientists have found a way to identify individual crashing waves using infrasound—acoustic waves with frequencies below the threshold of human hearing.
eos.org/articles/sci...
@qnishida.bsky.social
地震学の研究者。
Scientists have found a way to identify individual crashing waves using infrasound—acoustic waves with frequencies below the threshold of human hearing.
eos.org/articles/sci...
Wishing the best to all the friends and colleagues at JPL
13.10.2025 20:48 — 👍 1 🔁 1 💬 0 📌 0土星リングの地震学面白そう
Afigbo et al. (2025). Unveiling what makes Saturn ring: Quantifying the amplitudes of Saturn’s planetary normal‐mode oscillations and trends in C‐ring properties using kronoseismology (VII). JGR Planets, 130(4), e2024JE008710. doi.org/10.1029/2024...
サラ・オーグルヴィ『世界最高の辞典を作った名もなき人びと』(塩原道緒訳、早川書房、2025/09)
『オックスフォード英語辞典(OED)』は、英語の言葉について、書物に現れた用例を集めて載せる途方もない辞典です。
その用例収集には、多数のボランティアが関わっていたことが従来も知られていましたが、具体的にはよく分かっていませんでした。
本書は、第3版の編集に携わった著者が、用例蒐集の参加者「ディクショナリー・ピープル」(本書の原題でもあります)に光を当て、列伝風に紹介するすこぶるつきに面白い本です。
解説「みんな、OEDのイカした(一部イカれた)メンバーを紹介するよ!」を書きました。
From storm to the middle of the ocean: wave patterns observed by SWOT. In the middle of the storm on Cycle 25 track 515 (left) hitting California coasts from Monterey bay to Point Conception, track 580 (center), in the tropical Pacific on cycle 26 track 24 (right)
From storm to the middle of the ocean:in the tropical Pacific on cycle 26 track 24 (right), in the South Atlantic along track 214 hitting small icebergs (center top) iceberg A23-A (center) and in the middle of sea ice (center bottom), and in the tropical Atlantic near Benin on track 376.
🌊 Waves from storms. These pictures by SWOT (maps of SSH, dynamic range is -0.1 to 0.1 cm except for the leftmost panel at -1 to +1 m) show swell from the same storm "Eddie". Eddie peaked on 21 December 2024. The storm with the largest ocean waves in the past 10 years. Each panel is 40 by 40 km.
29.08.2025 12:14 — 👍 5 🔁 1 💬 1 📌 0Along‐Trajectory Acoustic Signal Variations Observed During the Hypersonic Re‐Entry of the OSIRIS‐REx Sample Return Capsule #SRL ⚒️
Sample return from asteroid Bennu can help scientists better understand how space junk enters the atmosphere.
pubs.geoscienceworld.org/ssa/srl/arti...
Thanks Princeton University Press, students and colleagues for
helping us make this textbook happen. Available widely in November. #tectonics #geodynamics #earthquakes
press.princeton.edu/books/hardco...
Mind the Gap! Three tectonic plates meet at the Chile Triple Junction, and a gap called a slab window lies beneath. New research narrows down exactly where this gap begins. eos.org/research-spo...
15.08.2025 14:09 — 👍 5 🔁 2 💬 0 📌 0On 21 october 2023 the source of similar rings is clearly the iceberg (some ice falling in the ocean?) odl.bzh/2gNlzvRS
15.08.2025 08:13 — 👍 3 🔁 1 💬 1 📌 0The seismic signal from Tracy Arm in Alaska, which was probably generated by a large landslide. Data released by the Alaska Earthquake Center.
Satellite image of Tracy Arm inlet. Image copyright Planet Labs, used with permission. Image dated 7 August 2025.
It is likely that a large, tsunamigenic landslide occurred in Tracy Arm inlet, in Alaska on 10 August 2025 at 5:30 am.
Seismic trace from the Alaska Earthquake Center, Satellite image (dated 7 August 2025 - before the landslide) from @planet.com.
eos.org/thelandslide...
SWOTといえば、最近Greenlandで発生した微動源と考えられてたSeiche (湾の固有振動) の直接観測に成功したという論文も印象的でした。
www.b-angle.bandogrp.com/media/observ...
Cool to see this paper out that uses a NASA SWOT altimeter to observe the 9-day water sloshing in Greenland triggered by a landslide tsunami that sent seismic waves around the world. A great effort that independently backs-up & substantially builds upon our prev work
www.nature.com/articles/s41...
We present a novel approach for high-resolution power spectral estimation under missing data conditions, assuming stochastic stationarity. This work comes from Balthazar's research during his internship.
05.08.2025 03:49 — 👍 1 🔁 0 💬 0 📌 0Our new paper is out!
Dubois-Dognon, B., & Nishida, K. (2025). Reconstruction of the autocorrelation function from segmented data and its application to the Earth’s seismic hum. Geophysical Journal International, (ggaf291), ggaf291. doi.org/10.1093/gji/...
今日も勝浦まだ30度超えずに持ちこたえてる!
05.08.2025 03:36 — 👍 0 🔁 0 💬 0 📌 0国立科学博物館、10月10日(金) ~ 2025年11月9日(日)の企画展は「学習マンガのひみつ」だって。
www.kahaku.go.jp/news/exhi_sc...
本体ではまだほとんど情報出てないけど、東洋文庫アカデミアが連携企画の講座受講者を募集している。こっちも面白そう。
toyo-bunko.or.jp/information/...
「歴史系学習マンガは歴史学の成果をどこまで表現できるのでしょうか。本講義では、学習マンガの戦前から今日にいたる歴史を俯瞰しつつ、社会文化の変容と学習マンガの描かれ方の変遷を検討……成果発信手段としての学習マンガの可能性についても考察」
Paper alert: Data mine paper regarding dense geophone (2 linear w/ sparsely scattered) array in LA basin. F.C-. Lin, R. W. Clayton, H. A. Ford, A. Allam, K. Gkogkas, V. Villa, H.J. Kim; LAB2022: A New Nodal Seismic Array Spanning the Los Angeles Basin. SRL doi: doi.org/10.1785/0220...
31.07.2025 00:54 — 👍 1 🔁 1 💬 1 📌 0Global Primary and Secondary Microseism Multi-Decade Geographic Variation, Secular Intensification, and Period Lengthening, Richard C. Aster, Thomas A. Lee, Frederik Jozef Simons, et al., ESS Open Archive . July 13, 2025. doi.org/10.22541/ess...
25.07.2025 15:15 — 👍 1 🔁 1 💬 0 📌 0「手と手がぶつかった瞬間はほとんど音がせず、両手の間の空洞の空気が、親指と人さし指の根本のすき間から噴き出す時に音が生じると分かった。また、その音の周波数は『ヘルムホルツ共鳴』と呼ばれる現象の理論式から導かれるものと一致した」
有料記事がプレゼントされました!7月23日 17:42まで全文お読みいただけます
拍手の正体、両手がぶつかりあう音じゃなかった 実験3年で明らかに:朝日新聞 digital.asahi.com/articles/AST...
This is a joke that makes me as a sighsmologist sad because I never made this joke.
03.07.2025 13:10 — 👍 15 🔁 1 💬 2 📌 0イタリアでは夏になると麦畑に古代ローマ時代の建物が浮かびあがる。地面の下に隠れている構造物が地中の水分に影響を与えて麦の穂の均一な成長を妨げるからだ。この現象はClopmarkと呼ばれている。
17.06.2025 23:46 — 👍 668 🔁 317 💬 1 📌 3C++11からUnicodeをサポートしているみたいなので、ギリシャ文字で式を書いてみたら、φとϕの表示が処理系によってひっくり返って混乱の極みだった。たしか以前pythonでも同じ間違いをしてたはず、、、
19.06.2025 12:20 — 👍 1 🔁 0 💬 0 📌 0Screenshot from live cam
Kilauea is erupting again! Beautiful views from all three USGS live webcams. ⚒️🌋
www.youtube.com/live/oG5zz9S...
We bury seismometers to keep them safe, at a stable temperature, and to contact hard rock to pick up the earth “breathing” at very low frequencies.
24.05.2025 09:19 — 👍 36 🔁 8 💬 3 📌 0Zhang, P., Nishida, K., & Fang, H. (2025). Reflective body waves extracted from 1 month of global microseisms illuminate the perturbed mantle transition zone beneath SW Japan. Geophysical Research Letters, 52, e2025GL116419. doi.org/10.1029/2025...
21.05.2025 11:49 — 👍 1 🔁 0 💬 0 📌 0It looks like the pear mode (0S3) of the Earth's normal mode.
www.youtube.com/watch?v=aMqM...
Distributed Acoustic Sensing (DAS) is a powerful tool for studying earthquakes, but DAS instruments can capture signals from many different sources. Check out what the DAS array near our the EarthScope Primary Instrument Center (EPIC) in New Mexico captured!
08.05.2025 18:26 — 👍 35 🔁 8 💬 2 📌 1WEBINAR RECORDING
Combining geodesy and collaboration to communicate local sea level change around Greenland
Presented by Margie Turrin and Lauren Lewright (Lamont-Doherty Earth Observatory)
www.youtube.com/watch?v=wog6...
NHKプラスで、スイッチインタビュー「角野隼斗×山下真由子」見ました。山下さんが自分の研究の話をするってことで講義が始まってしまい、でも番組としてはほとんどカットされて、でもすべての説明はホームページで見れますっていうのがすごくよかった。
www.nhk.jp/p/switch-int...
Geosciences is fun. Here is a cool paper about a X-ray laser: doi.org/10.1017/hpl.... which concludes: "ocean-generated microseism is a significant bottleneck that must be addressed to achieve femtosecond bunch arrival time stability in the sub-Hz regime."
01.05.2025 07:24 — 👍 2 🔁 1 💬 0 📌 0