Seismica Style Guide

Last updated January 2025

This page provides a few basic style guidelines for things like figure and table references, date/time formats, and units. Authors should try to follow these guidelines to the best of their ability. The Standards and Copy-Editing team will attempt to standardize articles post-acceptance, but the Seismica’s volunteer copy-editors would greatly appreciate authors’ help in preparing their articles according to this style guide.

Required by Seismica

Our copyeditors will check for the following style requirements. 

General rules

• Define Your Acronyms (DYA): The first use of all acronyms and initializations must be defined within text, with the abbreviation in parentheses. Any further use may simply use the acronym. Authors may elect to spell out acronyms an additional time at the first use in each section for longer papers.

• Proper use of dashes: Hyphens (-) link compound words. En dashes (–) are often used between two numbers to denote a range. Em dashes (—) can replace commas, colons, or periods to separate phrases. 

Figures, Tables, etc.

• Capitalization for Figures, Tables, equations, and Sections: When referring to a figure, table, or section in your article, capitalize “Figure”, “Table”, or “Section”. When referring to equations, do not capitalize.

• To abbreviate, or not to abbreviate? Using “Figure” versus “Fig.” (similarly, Table and Tab.; equation and eq.) is up to you. However, you should be consistent throughout your article. The simplest way to do this is to pick one form and stick to it: that is, use only the full words or only abbreviations throughout. Below are example sentences briefly demonstrating three possible ways you could consistently refer to items in your article:
• All abbreviated: As Figs 2 and 3 show, the correlation holds across the entire study region (mapped in Fig. 1). 
• None abbreviated: As Figures 2 and 3 show, the correlation holds across the entire study region (mapped in Figure 1). 
• Abbreviation only in parentheses: As Figures 2 and 3 show, the correlation holds across the entire study region (mapped in Fig. 1). 
• Plurals and abbreviations: When using the abbreviated forms for references, plurals do not have a trailing period. For example, the plural abbreviation for “Figures” is “Figs” rather than “Figs.” and the same extends to “Tabs” and “eqs”.
• Labeling components of a figure: When a figure has multiple sub-parts, label them alphabetically as a, b, c, etc. with lower-case letters. To reference a sub-part of a figure in the article text, use the number and letter with no space in between, as in “Figure 1a”. When describing the sub-parts of a figure in that figure’s caption, refer to those parts using one of these formats: “a.” or “(a)”. Again, consistency is key: use the same labeling scheme across all figures and figure captions in your manuscript. Note that for accepted papers, all sub-parts of a multi-part figure will need to be combined into a single image file, and you should include alphabetic labels for the sub-parts of the figure in that image file.
• Supplemental material: If you have a supplemental document that you refer to in your article, supplemental items should be labeled with the letter “S” and a number, as in “Supplemental Section S1” or “Supplemental Figure S4a”. Note that Seismica will not copy-edit or typeset supplemental documents.

Numbers and statistics

• Earthquake magnitudes: When magnitude refers to any kind of magnitude type, write as M<5, M≥7. Do not use spaces. For moment magnitude, use Mw or $\rm{M_w}$ in LaTeX. Write $M{<}5$ or $M{\geq}7$ to suppress extra spaces in math mode.

Best Practices

Our copyeditors won’t check for these, but here is a list of best practice guidelines.

• Statistical tests: For terms like p-value or t-test, italicize p, t. Hyphenate the term, and do not capitalize.
• Non-breaking spaces: Use non-breaking space (~ in LaTeX) between numbers and their units, when applicable. Examples: 30~s, $\rm{M_w}$~5.6.
• Use periods with lower case abbreviations (i.e., e.g., etc., a.k.a., p.m., vol., et al.)
• Don't use periods with upper case abbreviations (USA, BCE, GF, AAA, NASA, NATO)
• Do not abbreviate longitude or latitude
• Long form dates: Write long form dates as dd M yyyy: for example, 25 January 2022
• Short form dates: Write short form dates as dd/mm/yyyy: for example, 25/01/2022
• Times: Use 24-hour time. UTC is the default time zone unless otherwise specified. If you are using a different time zone, be sure to clarify, and do not assume the reader will know. Example times: 14:35, 14:35:22, 14:35:22.187, 07:35:22 PDT
• Items on this list do not need to be defined. This is not exclusive and all standard SI unit abbreviations are acceptable. LaTeX users may choose to use the siunitx package to typeset units, but this is not required.

km	kilometer
m	meter
sec (or s)	seconds
Hz	Hertz
° , deg	degrees (temperature or arc)
Pa	Pascals
kPa	kiloPascals
bar	bar
psi	pounds per square inch
Nm	Newton-meter
dyn-cm	dyne-centimeter
azm	azimuth
baz	backazimuth
ft	feet
mi	miles
nm	nanometer, nautical miles (context)