Know Your Geographical Knowledge In This Quiz

Explanation
A seismograph is the correct instrument used to measure earthquakes. A seismograph is a device that detects and records the vibrations caused by seismic waves. It consists of a pendulum or a mass on a spring that remains stationary while the Earth moves beneath it during an earthquake. The motion of the Earth causes the pen or stylus attached to the pendulum to move, which creates a graphical representation of the earthquake's intensity and duration on a rotating drum or paper. This measurement helps scientists analyze and understand earthquakes, including their magnitude, location, and potential impact.

Explanation
The point directly within the Earth where earthquakes originate is called the focus. This is the exact location where the seismic energy is released and the earthquake begins. The focus is typically located beneath the Earth's surface and can vary in depth. It is from the focus that seismic waves radiate outwards, causing the shaking and destruction associated with earthquakes. The epicenter, on the other hand, refers to the point on the Earth's surface directly above the focus.

Explanation
The shape of the Earth is called a geoid, which refers to the shape that closely represents the Earth's actual shape. The geoid is not a perfect sphere, but rather an irregular shape that takes into account the Earth's equatorial bulge and variations in its gravitational field. It is the most accurate representation of the Earth's shape and is used by scientists and cartographers for mapping and measurement purposes.

Explanation
Ferdinand Magellan is the correct answer because he was the first person to lead an expedition that successfully circumnavigated the world. In 1519, Magellan set sail with a fleet of five ships, and after three years of exploration, one ship and a handful of crew members completed the journey. Magellan's voyage proved that the Earth was round and significantly expanded geographical knowledge. Neil Armstrong was the first person to walk on the moon, Isaac Newton was a famous physicist, and Pavlov Michael is not a known historical figure.

Explanation
A lunar eclipse occurs when the Earth comes between the sun and the moon. During this phenomenon, the Earth blocks the sunlight from reaching the moon, causing the moon to appear darkened or reddish in color. This happens because the Earth's shadow is cast onto the moon's surface. Unlike a solar eclipse, where the moon comes between the sun and the Earth, a lunar eclipse can be observed from anywhere on the night side of the Earth.

Explanation
The time difference between longitudes is 4 minutes. This is because the Earth rotates 360 degrees in 24 hours, which means it rotates 15 degrees per hour. Since there are 60 minutes in an hour, dividing 60 by 15 gives us 4 minutes. Therefore, for every 15 degrees of longitude, there is a time difference of 4 minutes.

Explanation
The visibility of ships at sea proves that the Earth is spherical because as a ship moves farther away from the observer, it gradually disappears from view, starting from the bottom and eventually becoming completely hidden. This phenomenon can only be explained if the Earth is curved, as a flat surface would allow the entire ship to remain visible regardless of distance.

Explanation
The time required for the Earth to return to a given orbit with reference to a fixed solar star is called the sidereal year. A sidereal year is the time it takes for the Earth to complete one orbit around the Sun, measured with respect to the fixed stars. It is approximately 365.25 days long. This is different from a solar year, which is the time it takes for the Earth to complete one orbit around the Sun, measured with respect to the vernal equinox. The sidereal year is used by astronomers to track the motion of celestial objects.

Explanation
Oxygen is the most abundant element on the earth's crust. It makes up about 46.6% of the crust by weight. It is found in various forms, such as in minerals like quartz and silicates. Oxygen is essential for the formation of rocks and minerals, and it plays a crucial role in the Earth's geology and chemistry. Its abundance is due to its high reactivity and ability to combine with other elements.

Explanation
The core of the Earth is primarily composed of both iron and magnesium in the plastic state. This means that these elements are in a semi-solid, malleable form. The presence of iron and magnesium in the core is supported by seismic data and the understanding of Earth's composition. Iron is believed to be the main component, while magnesium is also present in significant amounts. This composition is crucial for the generation of Earth's magnetic field and the overall dynamics of our planet.