The Mid-Atlantic Ridge is a mid-ocean ridge, one of the largest geological features on the planet. As a consequence of the divergent motion between tectonic plates, there is a continuous occurrence of earthquakes. In this notebook, we propose a brief analysis of the Central and Southern Mid-Atlantic Ridge seismicity over the last 50 years. In addition, an analysis of a 6.9 Mw magnitude event was also done using seismograms and spectrograms from five different stations.
This notebook use an improved Capon method to obtain the arrival information, such as velocity and backazimuth of wavelets. This method uses an array of stations, so I searched for one using IRIS services and got an array of stations in Salt Lake City and obtained waveforms of some earthquakes and seismic noise to see the diferences when using active and passive signals. I also present a dispersion curve to see how the velocity varies with frequency. I hope you find it useful.
Volcanoes are very dynamic geological features and will generate seismic signals. When magma move up through the crust it will vibrate the surrounding rocks and generate a seismic signal. Magma intrusion can also cause brittle failure of rocks which generates a different seismic signal. This Notebook looks at the spectrograms of these volcanic-seismic signals generated during the 2004-2008 eruption of Mt. St. Helens and looks for differences in the spectrograms.
The first part of this notebook examines different earthquakes along the Andes Mountains, specifically from Peru, Chile, Ecuador, and Columbia. For the second part, the notebook plots earthquakes occurring in the same manner, except that this part examines strike-slip versus reverse earthquakes in the same areas, reverse vs reverse, and strike slip vs strike slip in different areas. For both parts, the goal is to try and find any unusual patterns in seismic activity before the earthquakes. This notebook is trying to see any sign of changes before any of the earthquakes, especially visible activity changes between reverse and strike slip earthquakes. It also tries to determine if there are similar patterns in the seismic activity for each earthquake compared to others in that area? The first plots search for any of these patterns, and the second plots creates histograms from the date/time information in order to look at the seismicity rate changes, especially over the past 10 years.
The purpose of this notebook is to analyse the seismicity in the southeasternmost Hawaiian island, hawai'i, spot trends, and to take a closer look at the three major earthquakes that happened in the region over the past five years. The island was built from five separated shield volcanoes that erupted somewhat sequentially, one overlapping the other. One of the volcanoes is inactive, two are dormant and two are currently active.
Central California is a seismically active region in the USA with earthquakes greater than magnitude 2.0 being a regular occurrence. This notebook will analyse the seismicity of the region and look to spot trends. Subsequently, the largest event in recent years was identified and a waveform was extracted. The signal was processed further in order to plot a spectogram and analyse the event in more detail.
The notebook analyses the energy, aftershock patterns and the seismicity for the 2001 Bhuj earthquake that took place on 26 January, 2001, India's 52nd Republic Day and remains one of the devastating seismic events in the history of India till date. It consists of two spectrograms, a plot to show magnitude of aftershocks and a histogram that showcases seismicity and its decay in the following weeks.
This analysis will focus on two neighboring regions in the state of Northrhine-Westphalia (Germany). While earthquakes in the Lower Rhine Graben (LRG) are mainly of tectonic origin, earthquakes in the Ruhr area are induced by mining activities. The first part of the analysis will compare an earthquake in the LRG to an earthquake in the Ruhr area and a WWII bomb explosion using spectrograms. The second part will demonstrate the spatial correlation between earthquakes and mines in the Ruhr area.
Visualization of the frequency response of seismological sensors and dataloggers helps Seismologists to determine the performance of these instruments. Furthermore, these are also important during the testing and calibration of instruments. In this work, bode plots for different sensors and dataloggers are generated using the DMC nominal response files and Obspy. Alternatively, this work also shows generating bode plots using poles and zeros as the inputs.
The notebook reviews the 2015 Colombia 6.2 Mw earthquake in Los Santos, on the Bucaramanga Nest (BN), which is the second most seismically active area in the world. Through the review of a seismogram, a spectrogram, and the literature on seismic nests; it is discussed the seismicity rate in the BN and is explained how the energy seen in the spectrogram helps to define a rough draft of the fracture that caused the earthquake.
This notebook studies the 2010 M 7.0 earthquake in Haiti and investigates why this earthquake was especially devastating. It considers potential reasons for the severe destruction, including both a lack of preparedness and the specific frequency content of the mainshock. By generating plots of magnitudes and seismicity rates, waveforms and spectrograms, this notebook analyzes possible explanations for the severe loss of life and property so as to be better prepared for future seismicity.
"Earthquake Fault" is an attraction at Inyo National Forests. This notebook explored the seismicity in that region from September 2000-2020 and compared it to that of Los Angeles, a known seismically active zone. A seismogram was also processed, following a recent earthquake felt in Los Angeles on Sept. 18, 2020.
Repeating earthquakes, are identical in location and geometry but occur at different times. They appear to represent recurring seismic energy release from distinct structures and their hosting environments also include volcanoes or subducted slabs in others. Small differences can be used to examine subtle changes in source properties or in material properties of the rocks, for that, his identification is useful for compression of the wide processes that occur in the earth.
A spectrogram is a visual way of representing the signal strength, or “loudness”, of a signal over time at various frequencies present in a particular waveform. Almost any earthquake in the world having a magnitude greater than 5.5 will be seen on these spectrograms. So, it is a visual way to represents earthquake intensity. In this project, we will use spectrogram to study earthquakes.
Fracking, a method of extracting oil and natural gas, has been sometimes linked to earthquakes. In this notebook, I aim to analyze the number of earthquakes and rates of seismicity in areas in the United States in which fracking has been heavily used. The purpose of this is to see whether seismicity has increased since the use of fracking began.
New Zealand has a long history of seismic activity given it's location along a subduction zone. This notebook is to look at the 7.8 magnitude Kaikōura earthquake that impacted the region in November 2016. Here we look at detecting the arrival of this earthquake at the nearest station and then take a look at the appearance of the event and look at changes in frequency over time. We also look at where these earthquakes are occurring in space and how it compares to previous events.
The purpose of this notebook is to analyze the 2004 Sumatra-Andaman Islands earthquake. This 9.1 magnitude earthquake is one of the most powerful earthquakes recorded worldwide and has been considered one of the most devastating natural disasters. This notebook will exam earthquake magnitudes and seismicity rates for 10 years prior to the 2004 earthquake and also take a closer look at data collected from three different recording stations within 1500 kilometers of the epicenter.
This notebook looks at the Tohoku earthquake of 2011 in Japan. Seismograms from a Japanese network are accessed. Analysis of the seismograms involves looking at the amplitude spectrograms and local noise before the earthquake. Finally, the location of the earthquake is put into perspective relative to all earthquake events catalogued in the Wilber3 IRIS catalogue. Finally, inferences are made on why the earthquake was so devastating.
El Salvador is a country that is located in Central America. The main reasons of the high seismicity in the country is the subduction zone, although local faults also can generate seismicity. Urban center in El Salvador lie in coast line, where the biggest earthquakes can produce tsunamies. The aplication of automatic phase picking algorithms can provide rapid earthquake notification allow us prevent disasters.
The coast of Chile has been recognized as one of the most seismically active regions in the world. To such extent, this region hosted the largest earthquake ever recorded in the world of magnitude 9.5 back in 1960. This Jupyter Notebook focuses on the seismic activity of this region, more specifically, the Valparaiso earthquake swarm and how it has been linked to other earthquake sequences that have occurred nearby in the megathrust plate in the past.
This notebook compares two seismic events that happened near the East Coast of Honshu, Japan. Both earthquakes have a magnitude greater than 6 MW. The location of these two events is very close, I suspect these two events have similar waveforms. Therefore, I requested the waveforms from the IRIS DMC and used the STA-LTA method to determine the arrival time. The length of the cross-correlation window is 200 seconds. However, the result did not show what I have expected.
Puerto Rico has experienced an unusual seismic activity since the last week of December 2019. This increase in seismicity was due to the Punta Montalva Fault that crosses the Lajas Valley, causing numerous disasters in the southern part of the island since the activity was mostly in the Guanica-Guayanilla area. To this day puertorricans still suffer the damage caused from the January 7 main-shock of magnitude 6.5. The notebook will show the graphs of this activity and its spectrogram.