Hsin-Hua Huang: Notes

Some notes for the research are collected/written here:

Data processing

SAC的時間概念
Filter中參數p的特性
A useful SAC commend: cuterr fillz (used to fill up zeros if there is no data point to cut in demanded time period)
IRIS web notes about common rotations in seismology
The SAC command interpolate for down-sampling is clearly aliasing once the sampling rate is less than 100 Hz, so the command decimate is always preferred.
The unit of the seismograms extracted from seed file is usually in meter, and that downloaded from STP with gain on is in centimeter (count is provided with gain off).
NetCDF user's guides [1][2][3]

Waveform simulation

The unit of displacement data downloaded from BATS is meter, which is the same with that of SEM synthetics but different from that of FK synthetics. The unit of FK synthetics is centimeter.
Since FK uses impulse function instead of step function as moment function, the output of FK is actually velocity seismograms/Green's functions, not displacement.

Instrument

The flat-response frequency band of Palert MEMS sensor ranges 0.05-15 Hz (ca. 0.1-10 conservatively).
Instructions for Raspberry shake's wifi setup
IRIS seed channel naming

Mathematics

Lagrage multiplier (拉格朗乘數)
Integration by parts (分部積分)
Mean and Variance of Sample Mean
連續隨機變數的期望值
微積分公式
The basics of Fourier transform
Frequency domain representation of the time delay
Geographic Distance and Azimuth Calculations [1][2]
A cool illustration of numerical optimization
An Intuitive (and Short) Explanation of Bayes' Theorem
Interpolation methods
Introduction to splines
PCA vs. ICA [1][2][3]
Bootstrap vs. Jackknife [1][2]
Animated math - An amazing website to make math and life easier!

English writing

英文論文寫作時態 [1][2]
To + V or To + Ving
While & When
For the reason - as/because; For this reason - therefore, thus
"Due to" is used as an adjective, and "because of" is used as an adverb.

Programming/OS

Comparable commands between Windows and Linux
Unix 重新導向跟 2>&1
Difference between calling by value, by address, and by reference in C/C++
Some useful Fortran tricks
遠端連線時Screen的用法
Install Torque on Centos 6
Install CentOS Extras repository
簡易Cluster架設 by鳥哥
Linux動態&靜態函式庫說明
Linux記憶體的運作方式[1][2][3]
Using the SAC library in Fortran/C codes
Default block size of binary files is different for ifort (4 bytes) and gfortran (1 byte), therefore using recl=1 for ifort is equivalent to uisng recl=4 for gfortran compiler
MPI vs OpenMP
rsync檔案同步與備份教學與範例
Transfer files from old to new Macbook [1][2]
Python | tutorial | Anaconda | ObsPy | w/ fortran | w/ C | tensorflow | PyTorch | Numba
Jupyter notebook | hot keys
Julia | Observer | Precompile | Multithreading | Examples
Modules: Pkg | IJulia | Seis | SAC | GMT | Flux | Knet | SciML | HTTP2 | Blink | CUDA | SeisIO | SeisNoise | Unet

Machine learning

機器學習入門 [1][2][3][4]
演算法分類 [1][2]
Unsupervised algorithms: K-means, SVM, Autoencoder
Supervised algorithms:
CNN vs RNN
U-net: [code][intro1][intro2]
Neural Networks and Deep Learning by Michael Nielsen

Miscellaneous

The wave-guided effect of subducted plate (with high-frequency content and sustained coda) observed in Taiwan region mainly takes place in a frequency band >3 Hz. (Chen et al., 2013)
The evocative "super-eruption" is an informal term referring to volcanic events in which at least 300 km^3 of magma are explosively evacuated from a subsurface magma chamber (Sparks et al. 2005). Any volcanic system that has produced a super-eruption is consequently dubbed a "super-volcano".
Characteristics of magma
Temperature of magmas (in Celsius): Basaltic magma - 1000-1200, Andesitic magma - 800-1000, rhyolitic magma - 650-800.
Density of magmas (in g/cm^3): Basaltic magma - 2.65-2.80, Andesitic magma - 2.45-2.50, rhyolitic magma - 2.18-2.25
Terminology aliases between solid Earth (left) and exploration (right) seismology:
source time function | source wavelet
epicentral distance | offset
seismogram | trace
station | receiver
seismic event | source
phase | event
Slowness u(s/deg) ~ u(s/km) * 111.91
Rule of Thumb: building natural frequency (s) ~ 1/10 *number of storey
Migration in practice
Linear vs. Non-linear elasticity

To-buy list

Structural geology algorithms: Vectors and tensors
An Introduction to the Theory of Seismology (2nd Edn)

NEWS & HIGHLIGHTS

2020/5/18:

Our work about detecting precursory seismic velocity changes (dv/v) prior to the 2018 May 2 Kilauea Hawaii volcano was accepted by Earth, Planets and Space, in which a spatiotemporal dv/v evolution in relation to multi-stage magma intrusion processes between the summit reservoirs and East Rift Zone dike system is illuminated and discussed.

2020/1/15:

IES & ESLab 2019 year-end party~

2019/12/4:

Congratulations to Kuan-Fu Feng who is awarded Outstanding Student Paper Awards in International Conferences by Earth Science Research Promotion Center (ESPRC)!

2019/9/27:

We are organizing a workshop on Frontiers in Seismic Interferometry on Sep. 27 and pleasant to have renowned experts from worldwide to join us! Please click and register if you are interested. We welcome everyone who'd like to learn or know more about this fast-growing research area in seismology.

2019/7/9:

Kicking off a seismic network deployment at Chunlin, Kaohsiung area for a integrative landslide monitoring project!

2019/6/19:

Congratulations to Jen Chu who received the grant of College Student Research Program from MOST!

2019/2/15:

ESLab go hiking for new year of the pig!

2019/1/12:

2018 year-end party of ESLab at Shin Yeh~

2019/1/9:

We are now recruiting an research assistant for the Academia Sinica thematic project of Landslide monitoring. Please click the [ad] for more details if you are interested! (position filled)

2018/12/5:

Our work using seismic and geodetic data to jointly constrain the multi-fault geometry and coseismic slips of the Hualien earthquake is just coming out on Geophys. Res. Lett.. 5-month postseismic data is also processed and shows significant displacement occurred at the Milun fault.

2018/8/31:

Congratulations to my summer program interns who won the 2nd position Poster Competition Award :)

2018/7/31:

Congratulations to Yu-Fang Hsu who received MOST College Student Research Award!

2018/7/14:

Our work about using near-field ground motion data to constrain earthquake rupture directivity in near real time has been accepted by Geophys. Res. Lett., which demonstrates a possibility of incorporating directivity information into EEW system for more accurate shaking alerts.

2018/5/3:

Congratulations to Yu-Fang Hsu who won outstanding student poster award in Geological and Geophysical Annual Meeting!

2018/3/20:

Based at Earthquake Research Institute, University of Tokyo as a visiting researcher for one month

2018/2/9:

Group photo of Earth Structure Lab taken at IES weiya party~

2017/10/18:

Our three series papers about planetary seismology has been accepted in journal Astrobiology and JGR this year, and in the one of JGR papers, we demonstrate the usefulness of seismic interferometry to obtaining discontinuity structure beneath single station in Europa.

2017/10/6:

Group photo for a dense geophone array deployment at Lantai landslide area

2017/9/1:

Congratulations to my summer program interns who won the 3rd position Poster Competition Award :)

2017/8/20:

We have recently developed a method to estimate primary rupture directivity in earthquake moment tensor inversion that has the potential to be automated in real time. The paper is just coming out in journal GJI.

2017/6/9:

Congratulations to En-Shih Wu who received the grant of College Student Research Program from MOST!

2017/3/17:

Seismology Forum 2017: Natural Hazards and Surface Processes is held this year on Mar 17 at IES, with a theme aiming to cover a wide range of topics such as landslide and volcanic hazards which recently gain much attention in Taiwan. Welcome to join us! [agenda]

2017/1/10:

Welcome to join the Earth Structure Laboratory (ESLab) at IESAS.

2016/10/08:

Two new papers about Mw 6.4 Meinong earthquake in southern Taiwan has been online! We discuss its triggered aseismic slips at a shallow fault [GRL], and the possible effects on anomalously large S-wave pulses striking Tainan area [TAO].

2016/10/01:

Officially move back to Taiwan and start a faculty position as assistant research fellow at Institute of Earth Sciences, Academia Sinica. Prospective students and postdocs enthusiastic about exploring Earth structure and seismotectonics are wanted!

2015/12/23:
Our new work using earthquake coda interferometry to probing inner core structure is published in journal GRL.

2015/05/15:
Employing joint inversion of local earthquake and teleseismic data, we unveiled the second larger magma reservoir in the lower crust beneath the Yellowstone. The works has been published in journal Science. (click the link for a 3-D demonstration of Yellowstone magamatic system)