Friday, January 13, 2023

Earthquakes with Depth

The World EQ Locator is an interactive map which visualizes the locations of historical earthquake data. The map also uses USGS data to show the locations and strengths of recent earthquake activity around the world. 

The map uses the ANSS Comprehensive Earthquake Catalog to plot the locations of historical earthquakes around the world. The marker for each earthquake on the map is colored to show the depth of its epicenter. The depth of each earthquake is also shown by its location on the 3D map in relation to sea level. Earthquakes can have depths from very near the Earth's surface to around 700 km deep. You can determine the exact measured depth of any earthquake by hovering over its marker on the map.

You can view the locations of recent earthquakes around the world by selecting the clock icon on the map. This will load a list of recent earthquakes recorded by the USGS. If you select any earthquake from this list its location will be shown on the map. The depth of selected earthquakes is also shown by the relative size of the vertical line shown above the earthquake's location on the map.

Another map which visualizes the depth of earthquakes is Earthquakes with Exaggerated Depth. Earthquakes with Exaggerated Depth is an interactive globe which visualizes one year's worth of earthquake activity around the world. The map was created by Esri's Raluca Nicola using data from the USGS.

On Raluca's transparent globe earthquakes which occurred between July 2017 and July 2018 are shown with their depth exaggerated by a factor of eight. Each earthquake is shown on the map using a colored circular marker. The color and size of the markers indicate the displayed earthquake's magnitude.

More than 75% of the world's volcanoes and around 90% of earthquakes occur in and around the basin of the Pacific Ocean. This area is commonly called the Ring of Fire. The reason for all this seismic activity in the Ring of Fire is the presence of converging tectonic plates.
The Pacific Ring of Fire can also be clearly seen on John Nelson's Seismic Illumination visualization. This map uses historical earthquake data going back to 1898 to show how earthquake activity reveals the Earth's tectonic plates. By concentrating on the Pacific Ring of Fire the map is able to show how continental drift causes seismic activity where the world's tectonic plates meet each other.

The Seismic Explorer interactive map also uses historical earhquake data to visualize 40 years of earthquake activity on Earth, including information on the magnitude, depth, and location of each recorded quake. The map uses data about recent seismic activity from the United States Geological Survey (USGS), and data from the Smithsonian Institution Global Volcanism Program on historical seismic activity around the world. 

On this map individual earthquakes are shown using colored and scaled markers. The colors of the markers represent earthquake depth and the size of the markers indicate the magnitude of the quake.The timeline control below the map allows you to view the seismic activity around the world for any date range. You can also press the play button to view an animation of global earthquakes from 1980 to the present day. 

Seismic Explorer also includes a cross section tool which allows you to view the depth data of earthquakes in a 3D view. You can use this tool to view an area of the globe as a cross-section, providing a three-dimensional view of the earthquake activity in that region. This allows you to view the depths of the earthquakes in that cross-section for any selected date range.

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