Trembler and Tremblor

A reader who has seen a common synonym for earthquake spelled more than one way asks,

Your guidance, please. “Trembler” or “Tremblor”?

Of the two, trembler is the acceptable choice.

“Tremblor” is a misspelling that conflates English trembler with Spanish temblor. The word temblor entered English from American Spanish in 1876. The Spanish noun temblor derives from the verb temblar, “to tremble.” Both Spanish temblar and English tremble are related to Latin tremulus, “trembling, shaking, quaking.”

All three words may be encountered in the media. The following examples are from online NBC news sources:

Last Tuesday’s 6.3-magnitude trembler killed at least 146 people and devastated the heart of picturesque Christchurch. 

Rafael Correa, who declared a national emergency, said the tremblor was the strongest quake to hit Ecuador since 1979.

Taiwan Earthquake: More Than 150 Missing After Deadly 6.4-Magnitude Temblor

Journalists who write “tremblor” have not paid attention to the article on earthquakes in The AP Stylebook:

The word temblor (not tremblor) is a synonym for earthquake.

Instead, they may have consulted Merriam-Webster, which includes “tremblor” as an alternative spelling for temblor.

It seems to me that the English word trembler works just as well as Spanish temblor as another word for earthquake. On the other hand, temblor seems to be the preferred term with earthquake specialists and in scientific journals.