Question

Fill in the blanks with the correct vocabulary word or words. Bits of rock or solidified lava dropped from the air after a volcanic eruption are __________.

Short answer

Tephra

Step-by-step solution

Understand the Context

To solve this problem, we first need to understand the context of volcanic activity and the vocabulary associated with it. Volcanic eruptions consist of various elements that are expelled from a volcano, including lava, ash, and other materials that solidify.

Identify Key Elements

The key elements in this question involve the solid materials that are expelled from a volcano and drop from the air after a volcanic eruption. We need to focus on the terminology related to volcanic materials.

Recall Related Vocabulary

Volcanic eruptions eject several types of materials, including ash, lapilli, volcanic bombs, and tephra. Each refers to different sizes or states of material, but they all relate to the fragments of both solidified and still-molten lava tossed into the air.

Match the Description to the Vocabulary

"Bits of rock or solidified lava dropped from the air after a volcanic eruption" commonly refer to general volcanic debris that falls back to the ground. "Tephra" is the term used to describe all the fragmented material ejected by a volcano regardless of size.

Key concepts

volcanic eruption

A volcanic eruption is a natural phenomenon where molten rock, ash, and gases from beneath Earth's crust are expelled. These eruptions occur due to the pressure building up from the magma, which is molten rock located beneath the Earth's surface. When this pressure becomes too great, it breaks through the crust, resulting in an eruption.

Volcanic eruptions can be either explosive or effusive. Explosive eruptions project a large amount of ash and debris high into the sky, while effusive eruptions allow lava to flow steadily out of the volcano multiple times. These events can drastically reshape landscapes and affect nearly all forms of life nearby.

During and after an eruption, volcanic activity creates a variety of phenomena important to understand. These include pyroclastic flows, which are hot gas and rock mixtures that travel down the sides of a volcano, and lava flows that form new land over time.

volcanic materials

Volcanic materials are the substances released by a volcano during an eruption. These materials vary greatly in size and type and can include:

• **Lava**: Molten rock that flows out of a volcano.
• **Ash**: Tiny fragments of volcanic glass, minerals, and rock expelled into the air.
• **Lapilli**: Pebble-sized material that falls during eruptions.
• **Volcanic bombs**: Larger particles launched into the air that solidify before hitting the ground.
• **Tephra**: A general term for all explosive volcanic debris, regardless of size.

Understanding these materials is critical because each can affect the environment and human activities differently.

For example, volcanic ash can travel over vast distances, disrupting air travel and covering landscapes. Larger volcanic bombs may only fall around the eruption site but can cause significant damage due to their size and speed.

lava solidification

Lava solidification is the process in which molten lava cools and turns into solid rock. This process begins as the lava flows out of a volcano and starts losing heat. The rate of cooling can greatly affect the texture and type of rock that forms.

The main factors that influence lava solidification include ambient temperature, the composition of the lava, and the rate of lava flow. Quick cooling, as often seen in ocean lava flows, results in volcanic glass or fine-grained rock. Slower cooling on land can create rougher, jagged rocks.

During solidification, the formation of new land begins. This process adds to the size of islands and mountain ranges, demonstrating how volcanic activity continuously reshapes the Earth's surface. By understanding how lava solidifies, scientists can better predict the evolution of landscapes after volcanic eruptions.