When basaltic lava flows in channels or lava tubes it can move up to 30 km/hr (19 mi/hr). How would this type of flow affect the time it took the lava to reach the town?

The time will be "2 hours".

Explanation:

Around 10 km/hr, lava eruptions were travelling. The vents was just 15 km (9.3 mi) away Kalapana city as well as 20 km (12.6 mi) from Pahoa city.  

So, we therefore need add the method, which would be: to taking out another time that civil defense officials just had to assess a city.

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Thus, to measure the time spent throughout the community of Kalapana,

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the answer is c on e2020, bud.