Earth Sci Q2 L2

Which of the following best describes an active volcano?

• Has no eruptive history

• Has erupted in historical times

• Is heavily weathered and inactive

Answer explanation

An active volcano is defined as one that has erupted in historical times. This distinguishes it from dormant or extinct volcanoes, which either have no recent activity or are heavily weathered and inactive.

Which of these volcanoes is considered the most active in the world?

• Mt. Etna

• Mt. Kilauea

• Mt. Mayon

Answer explanation

Mt. Kilauea is considered the most active volcano in the world due to its continuous eruptions since 1983, making it a prime site for volcanic activity, unlike Mt. Etna and Mt. Mayon, which are also active but less consistently.

How many active volcanoes are currently monitored by PHIVOLCS?

• 26

• 23

• 281

Answer explanation

PHIVOLCS currently monitors 26 active volcanoes in the Philippines. This number reflects their ongoing efforts to track volcanic activity and ensure public safety.

Which volcano is considered the most active in the Philippines?

• Mt. Mayon

• Mt. Taal

• Mt. Kanlaon

Answer explanation

Mt. Mayon is considered the most active volcano in the Philippines due to its frequent eruptions and well-documented activity. It is renowned for its perfect cone shape and has erupted over 50 times in recorded history.

What is the most dangerous volcanic eruption in history?

• Mt. Vesuvius, 79 AD

• Mt. Pinatubo, 1991

• Mt. Mayon, 2018

Answer explanation

Mt. Pinatubo's 1991 eruption was one of the largest in the 20th century, causing significant global climatic effects and over 800 deaths, making it the most dangerous eruption in history compared to the others listed.

Which volcano last erupted in 2018 with 52 historical eruptions?

(a)  

Answer explanation

The volcano that last erupted in 2018 and has a history of 52 eruptions is Mt. Mayon, located in the Philippines. Its frequent activity and historical significance make it a notable volcano.

Taal Lake represents which geological structure?

• Crater

• Caldera

• Fault line

Answer explanation

Taal Lake is a caldera formed by volcanic activity. A caldera is a large depression resulting from the collapse of a volcano after an eruption, distinguishing it from a crater, which is smaller and formed at the summit.

Mt. Kanlaon is known for being the highest mountain in which region?

• Luzon

• Mindanao

• Visayas

Answer explanation

Mt. Kanlaon is the highest mountain in the Visayas region of the Philippines, standing at 2,465 meters. It is a prominent landmark in Negros Island, distinguishing it from mountains in Luzon and Mindanao.

Which volcano is part of the Irosin Caldera?

• Mt. Bulusan

• Mt. Arayat

• Mt. Kanlaon

Answer explanation

Mt. Bulusan is the only volcano listed that is part of the Irosin Caldera, located in the Philippines. The other options, Mt. Arayat and Mt. Kanlaon, are not associated with this caldera.

How many inactive volcanoes are listed by PHIVOLCS?

• 23

• 281

• 26

Answer explanation

PHIVOLCS lists 26 inactive volcanoes in the Philippines. This number is specific and accurate, distinguishing it from the other options provided.