Geoscience Letters

http://link.springer.com/journal/40562

List of Papers (Total 111)

Resonance zones for interactions of magnetosonic waves with radiation belt electrons and protons

As an important plasma wave mode in the geospace, magnetosonic waves can interact with both radiation belt electrons and protons, thereby impacting the dynamics of magnetospheric particles. Based on the Doppler-shifted resonance condition and the cold plasma dispersion relation, we investigate the profiles of resonance zone and resonant frequency of the Landau resonance between...

Overestimation of the earthquake hazard along the Himalaya: constraints in bracketing of medieval earthquakes from paleoseismic studies

The Himalaya is one of the most seismically active regions of the world. The occurrence of several large magnitude earthquakes viz. 1905 Kangra earthquake (Mw 7.8), 1934 Bihar–Nepal earthquake (Mw 8.2), 1950 Assam earthquake (Mw 8.4), 2005 Kashmir (Mw 7.6), and 2015 Gorkha (Mw 7.8) are the testimony to ongoing tectonic activity. In the last few decades, tremendous efforts have...

Current structure and flow pattern on the electron separatrix in reconnection region

Results from 2.5D Particle-in-cell (PIC) simulations of symmetric reconnection with negligible guide field reveal that the accessible boundary of the electrons accelerated in the magnetic reconnection region is displayed by enhanced electron nongyrotropy downstream from the X-line. The boundary, hereafter termed the electron separatrix, occurs at a few d e (electron inertial...

Asteroid spin-rate studies using large sky-field surveys

Eight campaigns to survey asteroid rotation periods have been carried out using the intermediate Palomar Transient Factory in the past 3 years. 2780 reliable rotation periods were obtained, from which we identified two new super-fast rotators (SFRs), (335433) 2005 UW163 and (40511) 1999 RE88, and 23 candidate SFRs. Along with other three known super-fast rotators, there are five...

Transport properties of soil particles in Sakiyamawan–Amitoriwan nature conservation area, Iriomote Island, Japan

The actual states of soil particle transport in and exchange between the Sakiyama and Amitori bays, Iriomote Island, Japan, were investigated using atmosphere–ocean–river observations and numerical simulations. The results show that in summer in both bays large particles (≥15 μm) do not move from the vicinity of the river mouths. Small particles, however, do move to the...

Radiocarbon variability recorded in coral skeletons from the northwest of Luzon Island, Philippines

The North Equatorial Current (NEC) bifurcates at the eastern coast of the Philippines and moves northward as the Kuroshio, a North Pacific western boundary current. The NEC bifurcation point and Kuroshio variability are known to be affected by changes in climate such as the El Niño–Southern Oscillation and the pacific decadal oscillation. However, observational data are not...

Imaging of upper crustal structure beneath East Java–Bali, Indonesia with ambient noise tomography

The complex geological structures in East Java and Bali provide important opportunities for natural resource exploitation, but also harbor perils associated with natural disasters. Such a condition makes the East Java region an important area for exploration of the subsurface seismic wave velocity structure, especially in its upper crust. We employed the ambient noise tomography...

A meteor shockwave event recorded at seismic and infrasound stations in northern Taiwan

Three mysterious explosion sounds were heard in the coastal towns of Tamsui, west of Taipei in northern Taiwan, in the early evening of December 5, 2013. The event left clear signals that are identified in the recordings of 12 regional seismometers and 3 infrasound sensors and processed by means of travel time analysis. The apparent velocity of ~330 m/s of the signals confirms...

Implications of overestimated anthropogenic CO2 emissions on East Asian and global land CO2 flux inversion

Measurement and modelling of regional or country-level carbon dioxide (CO2) fluxes are becoming critical for verification of the greenhouse gases emission control. One of the commonly adopted approaches is inverse modelling, where CO2 fluxes (emission: positive flux, sink: negative flux) from the terrestrial ecosystems are estimated by combining atmospheric CO2 measurements with...

Occurrence of 1 ka-old corals on an uplifted reef terrace in west Luzon, Philippines: Implications for a prehistoric extreme wave event in the South China Sea region

Recent 230Th dating of fossil corals in west Luzon has provided new insights on the emergence of late Quaternary marine terraces that fringe west Luzon Island facing the Manila Trench. Apart from regional sea level changes, accumulated uplift from aseismic and seismic processes may have influenced the emergence of sea level indicators such as coral terraces and notches. Varied...

Re-examination of the age of historical and paleo-tsunami deposits at Koyadori on the Sanriku Coast, Northeast Japan

High-accuracy age estimations of tsunami deposits are very important for tsunami deposit research because the recurrence interval and frequency of tsunami deposits allow us to assess the devastating impacts of tsunamis in a populated country such as Japan. The correlation of tsunami events between remote coastal areas further enables us to constrain tsunami scenarios and fault...

Modeling large-scale human alteration of land surface hydrology and climate

Rapidly expanding human activities have profoundly affected various biophysical and biogeochemical processes of the Earth system over a broad range of scales, and freshwater systems are now amongst the most extensively altered ecosystems. In this study, we examine the human-induced changes in land surface water and energy balances and the associated climate impacts using a...

Auroral streamer and its role in driving wave-like pre-onset aurora

The time scales of reconnection outflow, substorm expansion, and development of instabilities in the terrestrial magnetosphere are comparable, i.e., from several to tens of minutes, and their existence is related. In this paper, we investigate the physical relations among those phenomena with measurements during a substorm event on January 29, 2008. We present conjugate...

Historical earthquake research in Austria

Austria has a moderate seismicity, and on average the population feels 40 earthquakes per year or approximately three earthquakes per month. A severe earthquake with light building damage is expected roughly every 2 to 3 years in Austria. Severe damage to buildings (I 0 > 8° EMS) occurs significantly less frequently, the average period of recurrence is about 75 years. For this...

The 2015 M w 6.0 Mt. Kinabalu earthquake: an infrequent fault rupture within the Crocker fault system of East Malaysia

The M w 6.0 Mt. Kinabalu earthquake of 2015 was a complete (and deadly) surprise, because it occurred well away from the nearest plate boundary in a region of very low historical seismicity. Our seismological, space geodetic, geomorphological, and field investigations show that the earthquake resulted from rupture of a northwest-dipping normal fault that did not reach the surface...

Testing the Coulomb stress triggering hypothesis for three recent megathrust earthquakes

We test the static Coulomb stress triggering hypothesis for three recent megathrust earthquakes (the 2004 Sumatra–Andaman earthquake, the 2010 Maule earthquake, and the 2011 Tohoku-Oki earthquake) using focal mechanism solutions for actual earthquakes as receiver faults to calculate Coulomb stress changes. For the 2004 Sumatra–Andaman and 2011 Tohoku-Oki earthquakes, the median...

Methodology to determine the parameters of historical earthquakes in China

China is one of the countries with the longest cultural tradition. Meanwhile, China has been suffering very heavy earthquake disasters; so, there are abundant earthquake recordings. In this paper, we try to sketch out historical earthquake sources and research achievements in China. We will introduce some basic information about the collections of historical earthquake sources...

A short history of Japanese historical seismology: past and the present

Since seismicity in Japan is fairly high, Japanese interest in historical seismicity can be traced back to the nineth century, only a few centuries after the formation of the ancient ruling state. A 1000 years later, 2 years earlier than the modern seismological society was founded, the research on historical seismology started in Japan in 1878. By the accumulation for the recent...

Change in the tropical cyclone activity around Korea by the East Asian summer monsoon

Correlation between the frequency of summer tropical cyclones (TCs) affecting Korea and the East Asian summer monsoon index (EASMI) was analyzed over the last 37 years. A clear positive correlation existed between the two variables, and this high positive correlation remained unchanged even when excluding El Niño-Southern Oscillation (ENSO) years. To investigate the causes of the...

Interdecadal variation of Korea affecting TC activity in early 1980s

By performing a statistical change-point analysis of activities of the tropical cyclones (TCs) that have affected Korea (K-TCs), it was found that there was a significant change between 1983 and 1984. During the period of 1984–2004 (P2), more TCs migrated toward the west, recurved in the southwest, and affected Korea, compared to the period of 1965–1983 (P1). These changes for P2...

Sedimentary environmental change induced from late Quaternary sea-level change in the Bonaparte Gulf, northwestern Australia

Low-latitude continental shelves, mixed siliciclastic–carbonate sedimentary systems, provide an understanding of sedimentary environments driven by paleoclimatological processes. The Bonaparte Gulf, northwestern Australian continental shelf, is among the widest in the world, ranging to 500 km, with shallow carbonate terraces and platforms that were exposed during periods of lower...

A trio-interaction theory for Madden–Julian oscillation

The Madden–Julian oscillation (MJO) is the dominant mode of tropical atmospheric intraseasonal variability and a primary source of predictability for global sub-seasonal prediction. Understanding the origin and perpetuation of the MJO has eluded scientists for decades. The present paper starts with a brief review of progresses in theoretical studies of the MJO and a discussion of...

Global cloud-permitting simulations of Typhoon Fengshen (2008)

Large-scale fields and inner-core processes relevant to the formation and intensification of Typhoon Fengshen (2008) were examined by simulations using a global nonhydrostatic model with a cloud-permitting resolution. Five runs were performed by varying the cloud microphysics or initial condition settings. In three out of five runs, a middle tropospheric trough developed within a...

Cross-disciplinary working in the sciences and humanities: historical data rescue activities in Southeast Asia and beyond

This paper argues that more work is needed to facilitate cross-disciplinary collaborations by scholars across the physical sciences and humanities to improve Data Rescue Activities (DARE). Debate over the scale and potential impact of anthropogenic global warming is one of the dominant narratives of the twenty-first century. Predicting future climates and determining how...

From written records to seismic parameters: the case of the 6 April 1667 Dalmatia earthquake

On Wednesday 6 April 1667, an earthquake occurred, and severely affected a large area of the eastern coast of the Adriatic Sea, also known as southern Dalmatia, in today Croatia, and part of Montenegro. This paper summarizes the seismological data existing today on this large earthquake, with special attention to how such data were gathered by means of investigating hitherto not...