On June 21, at noon there was an earthquake in my hometown. It wasn't anything serious, but it gave me inspiration to make this presentation on earthquakes.

• The presentation is intended to be informative and meet criteria of Developing Data Products week 3 assignment.

• The introductory information was taken from http://www.dummies.com/education/science/what-are-earthquakes/.

• The data shown in this presentation was downloaded from Kaggle (https://www.kaggle.com/usgs/earthquake-database).

An earthquake is the sometimes violent shaking of the ground caused by movements of Earth’s tectonic plates. Most earthquakes occur along fault lines, which is where two tectonic plates come together.

Earthquakes strike suddenly and violently and can occur at any time, day or night, throughout the year.

Earthquakes occur when large sections of the Earths’ crust — tectonic plates — shift.

There are seven primary tectonic plates (African, Antarctic, Eurasian, Indo-Australian, North American, Pacific, and South American) and a number of smaller, secondary and tertiary plates. Because of underlying movement in the Earth’s mantle, these plates can shift.

The Richter scale was developed in 1935 by Charles Richter to show the amount of energy released during an earthquake. It was originally intended not as an absolute measure of individual quakes but as a way to compare the relative strengths of different earthquakes. Though Richter measurements are generally thought of as being between 0 and 10, there are theoretically no limits to the scale in either direction.

The largest recorded earthquake was the 9.5-magnitude Great Chilean Earthquake of 1960. This quake spawned numerous tsunamis that caused damage as far away as Hawaii, Japan, and the Philippines.

The plot below shows earthquakes registered in years 1965 - 2016, of magnitude 5.5 or higher. The earthquakes clearly happen along the bodrers of tectonic plates (compare it with the picture on p.4).

You can toggle the legend to view selected magnitudes.

The earthquakes are characterized also by their focus and depth.

The focus of an earthquake is the actual point underground where rocks break. The depth of the focus can be categorized as shallow (up to 70 km below the surface), intermediate (70 to 300 km), or deep (greater than 300 km).

Below you see a chart of depth of the registered earthquakes. Toggle the legend for better view.