Do not put a hyphen between an adverb and the word it
modifies, e.g., horizontally layered.
Style of units
Physical quantities should be expressed in SI units. Exceptions
to this rule, at the discretion of the Editor, will be permitted when
field measurements were obtained or equipment was specified
with different units. In such cases, the value in non-SI units
should be followed by its equivalent in SI units, enclosed by
parentheses, e.g., 7200 ft/s (2200 m/s). Do not carry more significant
figures in the unit conversion than were used in the original
measurement. For example, note that 7200 ft/s converts to 2200
m/s, not 2195 m/s.
All of the following conform to SI metric standards:
s for seconds
ohm-m for ohm-meters
S/m for siemens/meter
Hz as unit, hertz as word
A as unit, ampere as word
F as unit, farad as word
H as unit, henry as word
V as unit, volt as word
J as unit, joule as word
N as unit, newton as word
W as unit, watt as word
Pa as unit, pascal as word
m/s for meters per second
1000 or 10 000 for 1,000 or 10,000
times sign instead of dot for multiplication
space between number and unit (10 m, not 10m)
mGal, not mgal
ms for milliseconds
GHz for gigahertz
MHz for megahertz
kHz for kilohertz
cm for centimeter
mm for millimeter
mm for micrometer
nm for nanometer
pm for picometer
The following exceptions to SI units are acceptable:
g/cc as density units
bar as pressure unit
gamma as magnetic field intensity unit
darcy as permeability unit