Critics have claimed the Bible is mostly fiction, including  the earthquake referred to in the Bible books of Amos and Zechariah.

“The words of Amos, one of the shepherds of Tekoa–the vision he saw concerning Israel two years before the earthquake, when Uzziah was king of Judah and Jeroboam son of Jehoash was king of Israel”—Amos 1:1 NIV

Recent geological studies have detected a massive seismic event, apparently a huge 8.2 earthquake, in the area where Amos lived. This event, which has been dated to around 760-750 BCE,  which was during the latter part of the long reign of Judean king Uzziah (792–740 BCE), and was the largest ever detected on the Dead Sea transform fault. 

Uzziah was a military and engineering genius (2 Chronicles 26:6-15), who became very prideful in his laters years. Notice:

“But once he was strong, his arrogance was such that it lead to his downfall; he was unfaithful to Yahweh his God by entering the Temple of Yahweh to burn incense on the altar of incense”—2 Chronicles 26:16 NJB

In reaction to Uzziah’s illegally entering “the Temple of Yahweh”, the high priest and 80 underpriests corrected him and ordered him to leave. Uzziah then flew into a rage (2 Chronicles 26:17,18).

“But at the very moment showed his anger to the priests, while they were looking at him in the house of the LORD beside the altar of incense, leprosy broke out on his forehead” (2 Chronicles 26:19 NAB).

It was apparently at this same point in time that the earthquake occurred. This earthquake was so powerful and memorable that it was used as a reminder two centuries later by the prophet Zechariah in predicting a future disaster. 

“You will flee by my mountain valley, for it will extend to Azel. You will flee as you fled from the earthquake in the days of Uzziah king of Judah. Then the LORD [Yahweh] my God will come, and all the holy ones with him”—Zechariah 14:5 NIV

The Jewish-Roman historian Josephus, 800 years after the earthquake, near the end of the 1st century, made reference to this event. He said the earthquake occurred at the same time that Uzziah was struck with leprosy by God:

“A great earthquake shook the ground, and a rent was made in the temple, and the bright rays of the sun shone through it; and fell upon the king’s face”—Antiquities of the Jews, Book X, paragraph 4

“This account of an earthquake at Jerusalem, and of the consequences of the earthquake, is exceeding like to a prophecy in Zech. xiv. 4,5; in which mention is made of ‘fleeing from that earthquake, as they fled from this earthquake in the days of Uzziah, king of Judah'” —footnote to the above

Josephus gives more details (which may, or may not, all be accurate) regarding king Uzziah than the Biblical account does, but the key point is that he confirms this earthquake as being a real event, “in the days of Uzziah king of Judah”.

Indeed, “the earthquake in the days of Uzziah king of Judah”, referred to in the Bible books of Amos and Zechariah, is just one of many thousands of pieces of evidence in support of the truth of the Bible’s authenticity.