LDEO Seismology: Long-Period Noise

Z45A-TA , LHN

Noise Levels at Different Periods

The table below gives the decibel 10% noise level (in db) for each month in several period bands. The 10% noise level is defined as the signal level not exceeded 10% of the time, based on hourly measurements. Each entry in the table is color coded with reference to the New Low Noise Model (NLNM, Peterson, 1993):
navy, -6 db < value-NLNM < -3 db
blue, -3 db < value-NLNM < 3 db
aqua, 3 db < value-NLNM < 6 db
lime, 6 db < value-NLNM < 9 db
yellow, 9 db < value-NLNM < 12 db
orange, 12 db < value-NLNM < 15 db
red, 15 db < value-NLNM < 20 db
fuchsia, 20 db < value-NLNM < 25 db
silver, value-NLNM < -6 db, value-NLNM > 25 db

Black indicates that there was an insufficient number of hourly measurements to calculate a noise level.

Noise levels (PSD) in decibels
Month Chan. Qual. # obs. 268s 228s 193s 164s 139s 118s 100s 85s 72s 61s 52s 44s 37s 32s 27s 23s 19s 16s 14s 12s 10s

201204 LHN AR 96 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

201202 LHN AR 168 -141 -143 -144 -145 -145 -147 -148 -148 -150 -151 -153 -154 -156 -158 -159 -160 -157 -153 -151 -150 -146

201112 LHN AR 24 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

201111 LHN AR 120 -142 -142 -142 -143 -144 -143 -144 -144 -146 -146 -147 -149 -151 -153 -155 -158 -156 -153 -150 -147 -145

201110 LHN AR 144 -155 -153 -154 -154 -154 -152 -154 -154 -154 -156 -158 -160 -163 -166 -167 -164 -158 -153 -150 -148 -144

201109 LHN AR 235 -157 -157 -158 -157 -157 -157 -156 -156 -156 -159 -162 -163 -166 -168 -169 -166 -158 -154 -150 -148 -147

201107 LHN AR 240 -150 -151 -154 -153 -155 -156 -156 -158 -159 -161 -163 -164 -167 -167 -166 -167 -162 -160 -158 -157 -153

201106 LHN AR 24 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999 999

201105 LHN AR 384 -145 -146 -147 -147 -146 -147 -147 -147 -149 -149 -152 -153 -155 -158 -160 -161 -159 -157 -156 -152 -150

201104 LHN AR 243 -144 -145 -145 -145 -145 -145 -146 -145 -146 -146 -148 -148 -150 -151 -152 -152 -152 -153 -153 -151 -146

Month	Chan.	Qual.	# obs.	268s	228s	193s	164s	139s	118s	100s	85s	72s	61s	52s	44s	37s	32s	27s	23s	19s	16s	14s	12s	10s
201204	LHN	AR	96	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
201202	LHN	AR	168	-141	-143	-144	-145	-145	-147	-148	-148	-150	-151	-153	-154	-156	-158	-159	-160	-157	-153	-151	-150	-146
201112	LHN	AR	24	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
201111	LHN	AR	120	-142	-142	-142	-143	-144	-143	-144	-144	-146	-146	-147	-149	-151	-153	-155	-158	-156	-153	-150	-147	-145
201110	LHN	AR	144	-155	-153	-154	-154	-154	-152	-154	-154	-154	-156	-158	-160	-163	-166	-167	-164	-158	-153	-150	-148	-144
201109	LHN	AR	235	-157	-157	-158	-157	-157	-157	-156	-156	-156	-159	-162	-163	-166	-168	-169	-166	-158	-154	-150	-148	-147
201107	LHN	AR	240	-150	-151	-154	-153	-155	-156	-156	-158	-159	-161	-163	-164	-167	-167	-166	-167	-162	-160	-158	-157	-153
201106	LHN	AR	24	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999	999
201105	LHN	AR	384	-145	-146	-147	-147	-146	-147	-147	-147	-149	-149	-152	-153	-155	-158	-160	-161	-159	-157	-156	-152	-150
201104	LHN	AR	243	-144	-145	-145	-145	-145	-145	-146	-145	-146	-146	-148	-148	-150	-151	-152	-152	-152	-153	-153	-151	-146