Natural > Earthquakes
Vector > Natural > Earthquakes
Data Source: USGS > Latest Earthquakes
Website: https://www.usgs.gov/programs/earthquake-hazards/earthquakes
Description
This layer shows a live feed of the latest Earthquakes throughout the world. The earthquakes are ordered by magnitude, so the largest ones are drawn over the smallest ones. In addition, details of the five Most Powerful Earthquakes (Maximum Magnitude, Location, Latitude, Longitude, Depth) will be listed on the Map Legend, which you can see on the Info Bar by typing the characters 'IB', or by viewing the dedicated Earthquake InfoBar page by typing the characters 'IQ'.
There are 15 overlays available: Past Day - Significant Earthquakes, Past Day - M4.5+ Earthquakes, Past Day - M2.5+ Earthquakes, Past Day - M1.0+ Earthquakes, Past Day - All Earthquakes, Past 7 Days - Significant Earthquakes, Past 7 Days - M4.5+ Earthquakes, Past 7 Days - M2.5+ Earthquakes, Past 7 Days - M1.0+ Earthquakes, Past 7 Days - All Earthquakes, Past 30 Days - Significant Earthquakes, Past 30 Days - M4.5+ Earthquakes, Past 30 Days - M2.5+ Earthquakes, Past 30 Days - M1.0+ Earthquakes, Past 30 Days - All Earthquakes, selectable through the 'Additional Layer Features' control on the 'Layers Menu'.
The Earthquake Icons can be configured in various ways, by opening the 'Layers Menu', selecting 'Natural > Earthquakes', and then clicking 'Change Point Style Settings'. This will open the dedicated 'Earthquake Style' window, where you can experiment with settings before applying them. An example Icon using the current settings is shown. Alter the 'Sample Magnitude Value' control to see it change.
The size of the Icon is related to Earthquake Magnitude. What looks good on one screen-resolution might not be appropriate for another, so you can alter the overall sizes with the 'Icon Magnification' control.
You can choose a common color and visibility for Icons by clicking 'Use Common Color'. The color is set by clicking 'Common Color'. Alternatively, you can have different colors and visibility for each range of magnitude by clicking 'Use Group Colors'. These colors and visibility-settings only apply to the current Map and the current 'User Style'.
The visibility is useful if you don't want to flood the map with all of the smallest of earthquakes. I like to hide all earthquakes with a magnitude of less than 3.0, by un-checking the first three ranges.
Another useful setting is the 'Magnitude Labels are drawn on Map from Magnitude Value' control. This sets the minimum magnitude that will show a label of the magnitude-value over the Icon. I like to set this to '5'. You can change the Label settings with the other controls in the 'Label Style' panel.
Background
The USGS estimates that several million earthquakes occur in the world each year, although many go undetected because they occur in remote areas or have very small magnitudes. The USGS now locates about 50 earthquakes each day; 20,000 a year. The USGS is working to improve its earthquake monitoring and reporting capabilities through the Advanced National Seismic System (ANSS), which is now about 40% completed. Full implementation of ANSS will result in 7,100 new instruments installed in the ground and in structures in high-risk urban areas, as well as a national backbone of modern seismic instruments covering the entire Nation. When completed, the ANSS will provide emergency response personnel with real-time information on the intensity and distribution of ground shaking that can be used to guide earthquake disaster response efforts. Similarly, information on building shaking will equip engineers with the data they need to improve future building designs to better withstand earthquake shaking.
This Map Layer is a Vector Layer composed of Points and Labels, so the Style for these can be changed as desired by opening the 'Layers Menu', clicking the wanted layer on the left, then clicking the relevant panel controls on the right.