The main difference between magma and lava is that magma is composed of molten rock and is stored in the Earth’s crust, while lava is the magma that reaches the surface of Earth through a volcano vent.
Simply put, magma is an extremely hot liquid and semi-liquid rock located under Earth’s surface. When magma flows onto Earth’s surface, we call it lava.
Key Areas Covered
1. What is Magma
– Definition, Features
2. What is Lava
– Definition, Features
3. Similarities Between Magma and Lava
– Outline of Common Features
4. Difference Between Magma and Lava
– Comparison of Key Differences
Andesitic magma, Basaltic magma, Lava, Magma, Rhyolitic magma, Volcano
What is Magma
Magma refers to an extremely hot liquid and semi-liquid rock situated under Earth’s surface. Earth is structured into four layers: inner core, outer core, mantle, and crust. The mantle layer mostly consists of magma. This magma pushes through holes and cracks in the Earth’s crust, resulting in a volcanic eruption.
Magma is a combination of minerals, which also include small amounts of dissolved gases like carbon dioxide, sulfur, and water vapour. Magma remains in its liquid state due to the high temperatures and the pressure under the Earth’s crust. Generally, when magma flows on to Earth’s surface through a volcanic vent, its viscosity influences the shape of the volcano. If magma is extremely viscous, volcanoes with steep slopes are formed. On the other hand, less viscous magma results in the formation of comparatively flatter volcanoes.
There are three main types of magma called Basaltic magma, Andesitic magma, and Rhyolitic magma. Each one of them has a unique mineral composition. However, all three types of magma contain a high content of silicon dioxide in varying percentages. When compared to the other two types, Basaltic magma is rich in iron, calcium, and magnesium. However, its potassium and sodium percentages remain low. Andesitic magma possesses minerals in moderate amounts, and Rhyolitic magma has a higher content of potassium and sodium but a lower percentage of magnesium, calcium, and iron.
What is Lava
Lava is the magma that flows or erupts onto Earth’s surface through volcanic vents. This molten rock mixture flowing downhill, glowing in a bright orange colour amid all the deep black smoke, is a visually mesmerizing scene.
Lava is extremely hot and cools down into deep black rocks reacting with the airflow. Lava has the capacity to reach a temperature of 1,250° Celsius. However, the average lava temperatures rise up to 750° Celsius, which is still a lot hotter than the maximum temperature your kitchen oven is capable of reaching.
Lava is a composition of silicon, oxygen, iron, magnesium, potassium, calcium and more. These minerals react under the Earth’s surface and sometimes produces crystals such as olivine, which is a beautiful yellow-green crystal we commonly call “peridot”. But, it is very hard to spot crystals on a lava rock which is usually dark grey, as these rocks reach the surface through volcanic vents before the mineral elements could turn into crystals beneath the ground.
Similarities Between Magma and Lava
- Lava and magma are exactly the same molten rock, except for the fact that magma is underground and lava is the magma that erupts onto Earth’s surface.
- Therefore, their mineral composition is the same.
Difference Between Magma and Lava
Magma is a burning hot liquid and semi-liquid rock situated under Earth’s surface while lava is the magma that erupts out of a volcano vent onto the surface of the Earth.
Magma is found below the Earth’s crust, whereas lava reaches the Earth’s surface.
Origin of Terminology
The term magma has an ancient Greek origin, while the term lava is of a Latin derivation.
Magma fluctuates in between a general temperature of 1300 to 2400 degrees Fahrenheit while lava fluctuates in between 1300 and 2200 degrees Fahrenheit.
In brief, magma is the molten rock that is underneath the Earth’s surface. When the magma shoots out of the volcano’s crater onto the surface of the earth, it is referred to as lava. Thus, this is the main difference between magma and lava.
1. “Volcanic Eruptions.” IFRC.